JP2015099297A - Multi-screen display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-screen display device that can appropriately control a light source according to a brightness mode.SOLUTION: In a multi-screen display device, a micro computer 43 calculates target brightness for each brightness mode; projection type video display devices 100 each identify a control current value to be a target, which corresponds to the target brightness calculated in accordance with the brightness mode set to each of the projection type video display devices 100; and the projection type video display devices 100 each supply a current indicating the identified control current value to a light source 34 of each of the projection type video display devices 100.

Description

  The present invention relates to a multi-screen display device including projection-type image display devices in which any one of a plurality of types of luminance modes is set.

  As a device for displaying video on a large screen, there is a multi-screen display device for displaying video on a multi-screen composed of the screens of a plurality of projection type video display devices. As a light source of each projection-type image display device constituting the multi-screen display device, for example, an optical device such as a high voltage discharge lamp or a light emitting diode (LED) which is a semiconductor light emitting element is used. Due to manufacturing variations of these optical devices, the luminance of the video displayed by each of the plurality of projection type video display devices may vary. When such luminance variation exists, a luminance difference between screens in a multi-screen is conspicuous, and the sense of unity of images displayed on the entire multi-screen may be impaired.

  Therefore, Patent Document 1 discloses a technique (hereinafter also referred to as related technique A) that suppresses variation in luminance of each screen in a multi-screen (screen). Specifically, in Related Art A, the luminance of light used for image formation is measured as needed in each projection-type image display device. And the measured brightness | luminance is shared among several projection type video display apparatuses. For example, the lowest luminance among the measured plurality of luminances is set as the target luminance. Next, each projection type video display device uses the relationship between the luminance value and the current value passed through the light source, and the current value for the luminance of the video displayed by the projection type video display device to be the target luminance. Set. Thereby, the brightness | luminance of the image | video which each projection type video display apparatus displays is brought close.

  Also in Patent Document 2, as in Patent Document 1, a technique for suppressing variation in luminance is disclosed.

Japanese Patent No. 3703361 JP 2012-150149 A

  However, multi-screen display devices composed of a plurality of projection-type image display devices are often used mainly in monitoring rooms such as roads, traffic, and plants. In these cases, depending on the time zone and display contents, there is a case where it is not always necessary to maximize the output luminance of all the projection type video display devices constituting the multi-screen display device.

  Each projection-type video display device constituting the multi-screen display device generally has a plurality of types of luminance modes in which the luminance of the video to be displayed is different. Therefore, in a multi-screen display device, in order to reduce power consumption, a specific projection type video display device is set with a luminance mode in which the luminance of the video is lower than the luminance mode of other projection type video display devices There is.

  In addition, when the number of the specific projection type video display devices to which the same luminance mode is set is plural, the variation in luminance is suppressed between the screens of the respective projection type video display devices to which the same luminance mode is set. There is a need to. In order to suppress the variation in luminance, it is necessary to control the light source suitable for the luminance mode set in each projection display apparatus. In Related Art A, the light source suitable for the luminance mode cannot be controlled.

  The present invention has been made to solve such a problem, and an object thereof is to provide a multi-screen display device capable of controlling a light source suitable for a luminance mode.

  In order to achieve the above object, a multi-screen display device according to an aspect of the present invention displays a video on a multi-screen composed of a plurality of projection-type video display devices communicating with each other. Each of the plurality of projection-type image display devices includes a light source that emits light having a luminance corresponding to a supplied current and includes a semiconductor light-emitting element, and each of the projection-type image display devices includes the projection-type image display device. Any one of a plurality of types of luminance modes in which the image luminance is a luminance of an image displayed by the device using light emitted from the light source is set, and each of the plurality of projection type image display devices further includes: A storage unit that stores a luminance characteristic that indicates a relationship between a control current of the light source and the video luminance as a luminance corresponding to the control current, and is one of the plurality of projection-type video display devices The first projection type video display device includes the video brightness that can be output by the first projection type video display device, and a second projection type other than the first projection type video display device among the plurality of projection type video display devices. Video display device can output And a calculation unit that calculates a target luminance, which is a target luminance, for each of the luminance modes based on the video luminance, and each of the projection type video display devices uses (a) the luminance characteristic. A control current value that is a value of the control current corresponding to the target brightness calculated corresponding to the brightness mode set in the projection display apparatus and that is a target, and (b) ) Supplying the current indicating the specified control current value to the light source of the projection display apparatus.

  According to the present invention, the calculation unit calculates the target luminance for each luminance mode. Each of the projection type video display devices specifies a target control current value corresponding to the target luminance calculated corresponding to the luminance mode set in the projection type video display device. Each of the projection type video display devices supplies a current indicating the specified control current value to the light source of the projection type video display device.

  Thereby, the light source suitable for the luminance mode can be controlled. Therefore, it is possible to suppress variations in luminance among the projection type video display devices in which the same luminance mode is set.

It is a figure which shows the structure of the multi-screen display apparatus which concerns on Embodiment 1 of this invention. It is a figure for demonstrating a multiscreen. It is a block diagram which shows the structure of the projection type video display apparatus concerning Embodiment 1 of this invention. It is a figure which shows an example of a brightness | luminance characteristic. It is a flowchart of a brightness adjustment process. It is a figure which shows the state of the brightness | luminance mode set to each projection type video display apparatus. It is a figure which shows an example of a chromaticity characteristic. It is a flowchart of a brightness chromaticity adjustment process. It is a figure for demonstrating the method for calculating target chromaticity. It is a figure which shows the characteristic brightness | luminance which each projection type video display apparatus can output. In a comparative example, it is a figure which shows transition of the target luminance when the luminance mode is changed. It is a flowchart of target luminance calculation processing A1. It is a figure for demonstrating the target luminance calculation process which concerns on Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof may be omitted.

<Embodiment 1>
FIG. 1 is a diagram showing a configuration of a multi-screen display apparatus 1000 according to Embodiment 1 of the present invention. Although the details will be described later, the multi-screen display device 1000 is composed of a plurality of projection-type video display devices capable of projecting video light constituting a video on a screen (screen). The multi-screen display device 1000 is a device that displays a video on a multi-screen composed of a plurality of projection-type video display devices that communicate with each other. Hereinafter, the multi-screen display device 1000 will be specifically described.

  As shown in FIG. 1, the multi-screen display device 1000 includes projection type image display devices 100a, 100b, 100c, and 100d. Each of the projection type video display devices 100a, 100b, 100c, and 100d has the same configuration, although details will be described later. Hereinafter, each of the projection type video display devices 100a, 100b, 100c, and 100d is also simply referred to as the projection type video display device 100. That is, the multi-screen display device 1000 includes four projection video display devices 100.

  In addition, the number of the projection-type image display devices 100 constituting the multi-screen display device 1000 is not limited to 4, and may be 2, 3 or 5 or more.

  Each projection video display apparatus 100 has a plurality of types of luminance modes for changing the luminance of the video. Each of the projection type video display devices 100 is set with one of a plurality of types of luminance modes. Details of the luminance mode will be described later.

  Projection type video display devices 100a, 100b, 100c, and 100d include screens 10a, 10b, 10c, and 10d shown in FIG.

  The multi-screen display device 1000 includes a multi-screen 10A. As shown in FIG. 2, the multi-screen 10A is a single screen composed of screens 10a, 10b, 10c, and 10d arranged in a matrix. In the following, each of the screens 10a, 10b, 10c, and 10d is also simply referred to as a screen 10. The screen 10 is a screen on which image light constituting an image is irradiated. The number of screens constituting the multi-screen 10A is not limited to 4, and may be 2, 3 or 5 or more.

  The projection display apparatuses 100a, 100b, 100c, and 100d are configured to communicate with each other using the communication cable 7. Each projection display apparatus 100 is assigned a unique ID number (ID1 to ID4) that is not duplicated. Specifically, ID1, ID2, ID3, and ID4 are assigned to the projection display apparatuses 100a, 100b, 100c, and 100d, respectively.

  Any of the plurality of projection type video display devices 100 constituting the multi-screen display device 1000 functions as a master device, and the projection type video display devices 100 other than the master device function as slave devices.

  In the present embodiment, as an example, the projection display apparatus 100a to which the ID number “ID1” is assigned functions as a master apparatus. Further, the projection type video display devices 100b, 100c, and 100d to which the ID numbers “ID2”, “ID3”, and “ID4” are assigned function as slave devices.

  The projection type video display device 100a as a master device controls the projection type video display devices 100b, 100c, and 100d as slave devices in an integrated manner. The projection display apparatus 100a can communicate with the projection display apparatuses 100b, 100c, and 100d using the communication cable 7.

  In the following, the projection display apparatus 100a is also referred to as a master apparatus Ma. In the following, the projection type video display devices 100b, 100c, and 100d are also expressed as slave devices Sb, Sc, and Sd, respectively.

  The multi-screen display device 1000 displays video on the multi-screen 10 </ b> A when each projection video display device 100 displays video on the screen 10.

  FIG. 3 is a block diagram illustrating a configuration of the projection display apparatus 100 as a master apparatus or a slave apparatus. FIG. 3 also shows a video source device 5 and an external control device 6 that are not included in the projection video display device 100.

  The video source device 5 is a device that outputs a video signal to each projection type video display device 100 constituting the multi-screen display device 1000. That is, a video signal is input to each projection video display device 100.

  The external control device 6 is configured to be communicable with each projection type video display device 100 constituting the multi-screen display device 1000. That is, each projection video display device 100 communicates with the external control device 6.

  The external control device 6 is, for example, a PC (Personal Computer). The external control device 6 includes a user interface for operating the external control device 6. The user interface is a keyboard, a mouse, or the like. The external control device 6 has a function of controlling each projection type video display device 100 constituting the multi-screen display device 1000 in accordance with a user interface operation by the user.

  As shown in FIG. 3, the projection display apparatus 100 includes a screen 10, a projection unit 3, and a power supply circuit unit 4. The projection unit 3 projects video light onto the screen 10 based on the video signal. The power supply circuit unit 4 gives a video signal subjected to predetermined signal processing to the projection unit 3.

  Next, each configuration will be described in detail. First, the power supply circuit unit 4 will be described in detail. The power supply circuit unit 4 includes a video input circuit 41, a video processing circuit 42, a microcomputer 43, and a memory 44.

  The video input circuit 41 receives a video signal output from the video source device 5 arranged outside the multi-screen display device 1000. Next, the video input circuit 41 of the projection video display apparatus 100 converts the received video signal into a digital signal, and outputs the converted digital video signal to the video processing circuit 42.

  As will be described in detail later, the video processing circuit 42 performs image processing such as image quality adjustment on the image indicated by the received digital video signal. Next, the video processing circuit 42 performs digital signal format conversion that converts the image-processed digital video signal into a video signal in a format that can be processed by the projection unit 3 (video display device 31 described later).

  Hereinafter, red, green, and blue are also expressed as R, G, and B, respectively. The digital video signal processed by the video processing circuit 42 indicates an R signal, a G signal, and a B signal.

  Here, the image quality adjustment performed by the video processing circuit 42 will be described. The video processing circuit 42 has an image quality adjustment function that independently increases or decreases the levels of the R, G, and B signals that are the three primary colors indicated by the digital video signal for each pixel and each primary color constituting the video. Yes.

  In the present embodiment, the video processing circuit 42 is equipped with a calculation function for performing a 3 × 3 matrix calculation represented by the following equation 1 with respect to the levels of the R, G, and B signals indicated by the digital video signal. ing. The video processing circuit 42 performs image quality adjustment by performing the calculation of Expression 1.

  In Equation 1, Ri, Gi, and Bi indicate the levels of the R, G, and B signals indicated by the digital video signal input to the video processing circuit 42, respectively. In Equation 1, RR, RG, RB, GR, GG, GB, BR, BG, and BB are correction coefficients. In Equation 1, Ro, Go, and Bo respectively indicate the levels of the corrected R, G, and B signals that are corrected by the correction coefficient.

  According to the calculation of Expression 1, for example, the signal level of Ro is obtained by adding and decreasing the signal levels of Gi and Bi to those obtained by increasing or decreasing the signal level of Ri. The image processing circuit 42 performs the adjustment of luminance and chromaticity of R color (mainly chromaticity adjustment) as the above-described image quality adjustment function by performing the calculation of Expression 1.

  In the second embodiment to be described later, the correction coefficient of Expression 1 is calculated by a microcomputer 43 described later, and the video processing circuit 42 uses the calculated correction coefficient as the correction coefficient of Expression 1. The video processing circuit 42 performs the digital signal format conversion described above on the video signal after image quality adjustment. Hereinafter, a signal obtained by digital signal format conversion is also referred to as a converted digital signal. Then, the video processing circuit 42 outputs the converted digital signal to the video display device 31 of the projection unit 3 at a timing according to an instruction from the microcomputer 43.

  The memory 44 is a storage unit for storing information, data, and the like.

  The microcomputer 43 is controlled by the external control device 6 disposed outside the multi-screen display device 1000. Moreover, although the details will be described later, the microcomputer 43 comprehensively controls each component of the projection video display device 100.

  Next, the projection unit 3 will be described in detail.

  The projection unit 3 includes a video display device 31, a projection lens 32, a photosynthesis device 33, a light source 34 </ b> L, a light source driver 35, and a luminance sensor 36.

  The video display device 31 is, for example, a DMD (Digital Micromirror Device). That is, each projection-type image display device 100 is a single-plate device using one DMD. Note that the video display device 31 is not limited to the DMD, and may be another video display device.

  The light source 34L is a light source that sequentially emits light of three primary colors (red light, green light, and blue light).

  The light source 34L includes light sources 34R, 34G, and 34B. Each of the light sources 34R, 34G, and 34B is a semiconductor light emitting element. Each of the light sources 34R, 34G, 34B is, for example, an LED. The light source 34R is a red light source that emits red light. The light source 34G is a green light source that emits green light. The light source 34B is a blue light source that emits blue light.

  Hereinafter, each of the light sources 34R, 34G, and 34B is also simply referred to as a light source 34. That is, each of the plurality of projection type video display devices 100 constituting the multi-screen display device 1000 includes a light source 34 made of a semiconductor light emitting element. The light source 34 emits light having a luminance corresponding to the magnitude of the current flowing through the light source 34. That is, the light source 34 emits light having a luminance corresponding to the supplied current. The brightness of the light emitted from the light source 34 is different for each brightness mode set in the projection display apparatus 100.

  Although details will be described later, the projection display apparatus 100 displays an image using light emitted from the light source 34. Hereinafter, the luminance of the image displayed by the projection display apparatus 100 using the light emitted from the light source 34 is also referred to as image luminance. The video brightness is the brightness of the video displayed on the screen 10.

  Each of the projection type video display devices 100 constituting the multi-screen display device 1000 is set with any of a plurality of types of luminance modes having different video luminances.

  The setting of the brightness mode of the projection display apparatus 100 is performed by a user operation on the external control device 6. In the following, the luminance mode set in the projection display apparatus 100 is also referred to as a set luminance mode.

  In the present embodiment, the plurality of types of luminance modes are assumed to be a normal mode and a power saving mode, as an example. The normal mode is a mode in which the video brightness is higher than the power saving mode. The power saving mode is a mode in which the video brightness is lower than that in the normal mode. The amount of current supplied to the light source 34 in the power saving mode is smaller than the amount of current supplied to the light source 34 in the normal mode. That is, the power saving mode is a mode in which the power consumption of the projection display apparatus 100 is smaller than that in the normal mode.

  In the power saving mode, the lower limit of the amount of current supplied to the light source 34 is not the viewpoint of the brightness of the image when the user views the screen 10, but various types of components constituting the projection display apparatus 100. Determined by electronic circuit. The video brightness in each brightness mode is determined in advance.

  The memory 44 further stores luminance mode information in advance. The luminance mode information is information for specifying the type of luminance mode. Hereinafter, the luminance mode information indicating that the luminance mode of the projection display apparatus 100 is the normal mode is also referred to as luminance mode information α. The luminance mode information α indicates the mode identifier “α”. The mode identifier “α” indicates that the luminance mode is the normal mode.

  Hereinafter, the luminance mode information indicating that the luminance mode of the projection display apparatus 100 is the power saving mode is also referred to as luminance mode information β. The luminance mode information β indicates the mode identifier “β”. The mode identifier “β” indicates that the luminance mode is the power saving mode.

  The memory 44 stores brightness mode information corresponding to the brightness mode set in the projection display apparatus 100. For example, when the luminance mode set in the projection display apparatus 100 is the normal mode, the luminance mode information α is stored in the memory 44.

  Note that the luminance mode is not limited to two types of the normal mode and the power saving mode, and may be three or more types.

  The light source driver 35 controls the light sources 34R, 34G, and 34B of the light source 34L to emit light. Specifically, the light source driver 35 controls the light sources 34R, 34G, and 34B in accordance with instructions from the microcomputer 43 so that red light, green light, and blue light are sequentially emitted at different timings (time division). .

  More specifically, the light source driver 35 supplies a control current (drive current) to each light source 34 in order to cause each light source 34 to emit light. The control current is a current for controlling the luminance of light emitted from each light source 34. The light source driver 35 supplies the control current to each light source 34 in a time division manner. Thereby, the timing at which the light source 34L emits light is controlled in a time-sharing manner.

  The photosynthesizer 33 sequentially emits red light, green light, and blue light emitted from the light sources 34R, 34G, and 34B, respectively.

  The light emitted from each of the light sources 34R, 34G, and 34B is irradiated to the video display device 31 via the photosynthesis device 33 and then irradiated to the screen 10 via the projection lens 32. Note that red light, green light, and blue light are sequentially irradiated onto the screen 10 at very short time intervals.

  Therefore, the user who views the screen 10 appears to irradiate the screen 10 with a composite image of the red light image, the green light image, and the blue light image. That is, the user can see a mixed color of red, green, and blue on the screen 10. As a result, a full-color image is displayed on the screen 10.

  The video display device 31 intensity-modulates the irradiated light in accordance with the converted digital signal received from the video processing circuit 32 and guides the modulated light to the projection lens 32.

  The microcomputer 43 controls the luminance of light emitted from each of the light sources 34R, 34G, and 34B via the light source driver 35. Specifically, the microcomputer 43 controls the control current supplied to each of the light sources 34R, 34G, and 34B via the light source driver 35. The microcomputer 43 is configured to be able to access the memory 44. The microcomputer 43 stores the luminance characteristics of red light, green light, and blue light and various data in the memory 44 in advance. That is, the memory 44 stores the luminance characteristics of red light, green light, and blue light of the projection display apparatus 100 including the memory 44. Further, the microcomputer 43 reads the luminance characteristics, various data, and the like stored in the memory 44 as necessary.

  The luminance characteristic is a characteristic indicating the relationship between the control current of the light source 34 and the video luminance corresponding to the control current. Hereinafter, the current value (value) of the control current for operating the light source 34 is also referred to as a control current value. In the following, video brightness obtained only with red light, video brightness obtained only with green light, and video brightness obtained only with blue light are also referred to as R brightness, G brightness, and B brightness, respectively.

  FIG. 4 is a diagram illustrating an example of luminance characteristics. FIG. 4A is a diagram illustrating an example of the luminance characteristic LR1 corresponding to the light source 34R that emits red light. In FIG. 4A, YR0 means that the control current value of the light source 34R is IR0, and the screen 10 displays an image by only irradiating the screen 10 with red light emitted from the light source 34R. It is the video brightness in the state.

  FIG. 4B is a diagram illustrating an example of the luminance characteristic LG1 corresponding to the light source 34G that emits green light. In FIG. 4B, YG0 means that the control current value of the light source 34G is IG0, and only the green light emitted from the light source 34G is irradiated onto the screen 10 so that the screen 10 displays an image. It is the video brightness in the state.

  FIG. 4C is a diagram illustrating an example of the luminance characteristic LB1 corresponding to the light source 34B that emits blue light. In FIG. 4C, YB0 means that the control current value of the light source 34B is IB0, and the screen 10 displays an image when only the blue light emitted from the light source 34B is irradiated onto the screen 10. It is the video brightness in the state.

  Hereinafter, each of the luminance characteristics LR1, LG1, and LB1 is also simply referred to as a luminance characteristic L. The luminance characteristic L is a current luminance characteristic indicating the relationship between current (control current) and luminance (video luminance).

  Further, by controlling the amount of control current supplied to the light source 34, the luminance of the light emitted from the light source 34 can be controlled. Therefore, in the present embodiment, control current values corresponding to the different brightness modes described above are stored in the memory 44 in advance. That is, the memory 44 stores a control current value corresponding to each luminance mode.

  In the present embodiment, the initial setting values I0_α and I0_β of the light sources 34R, 34G, and 34B are stored in advance in the memory 44 of each projection display apparatus 100. The initial set value I0_α is an initial control current value corresponding to the normal mode as the luminance mode. I0_α is, for example, 30 (A). The initial set value I0_β is an initial control current value corresponding to the power saving mode as the luminance mode. I0_β is, for example, 15 (A).

  Although details will be described later, it is assumed that the user performs an operation on the external control device 6 to change the luminance mode of the projection display apparatus 100. In this case, the microcomputer 43 reads out the control current value corresponding to the luminance mode after the change from the memory 44 and performs control for supplying the control current of the control current value to the light source 34. Thus, the user can quickly switch the luminance of the video displayed by the projection display apparatus 100.

  The microcomputer 43 of the master device Ma and the microcomputers 43 of the slave devices Sb, Sc, and Sd are configured to be able to transmit and receive information to and from each other via the communication cable 7 and a communication interface (not shown). Is done. For example, the microcomputer 43 of the master device Ma transmits a control command to each of the microcomputers 43 of the slave devices Sb, Sc, Sd via the communication cable 7.

  The microcomputer 43 of the master device Ma and each of the microcomputers 43 of the slave devices Sb, Sc, Sd may be configured to be able to communicate without using the communication cable 7. For example, each of the master device Ma and the slave devices Sb, Sc, Sd may have a function of performing wireless communication with each other.

  The luminance sensor 36 detects the light amount for the microcomputer 43 to detect the light amount (luminance) of the image light projected on the screen 10. The luminance sensor 36 transmits the detected amount of image light to the microcomputer 43. In the present embodiment, the luminance sensor 36 receives unnecessary light that is not projected on the screen 10 from the video display device 31 in the projection unit 3, detects the amount of the unnecessary light, and sends the detected amount of light to the microcomputer 43. Send.

  The microcomputer 43 artificially detects (monitors) the luminance (video luminance) of the video light projected on the screen 10 based on the received light quantity. When a liquid crystal image display device is used as the projection unit 3, the microcomputer 43 may detect the image luminance in a pseudo manner based on the amount of light from the backlight.

  Each projection-type image display device 100 performs a characteristic calculation process at the time of factory shipment or product image adjustment. In the characteristic calculation step, the projection display apparatus 100 calculates each of the luminance characteristics LR1, LG1, LB1 shown in FIGS. Specifically, for each of R, G, and B, the projection display apparatus 100 changes the brightness (video brightness) on the screen 10 corresponding to the control current of each light source 34 while changing the control current. Measurement is performed using the sensor 36.

  For example, the projection display apparatus 100 supplies the control current only to the light source 34R, and uses the luminance sensor 36 while changing the control current in a state where only the red light is irradiated on the screen 10. Measure brightness. Thereby, the luminance characteristic LR1 is calculated. The luminance characteristics LG1 and LB1 are also calculated in the same manner as the luminance characteristics LR1.

  Thereby, the projection display apparatus 100 calculates the luminance characteristics LR1, LG1, LB1. Then, the projection display apparatus 100 stores the calculated luminance characteristics LR1, LG1, LB1 in the memory 44 of the projection display apparatus 100. As a result, the luminance characteristics LR1, LG1, and LB1 are stored in the memory 44. That is, the memory 44 of each projection display apparatus 100 stores the luminance characteristics LR1, LG1, LB1 corresponding to the projection display apparatus 100.

  Note that the measurement of the video luminance may be performed by the following process A in which the luminance sensor 36 is not used. In step A, for example, the operator operates the external control device 6 so that the projection display apparatus 100 irradiates the screen 10 only with red light. The operator measures the video brightness on the screen 10 using an illuminometer. Then, the operator operates the external control device 6 to measure the video brightness on the screen 10 every time the control current of the light source 34R is changed.

  Thereby, the operator obtains the luminance characteristic LR1. Then, the operator operates the external control device 6 so that the obtained luminance characteristic LR1 is stored in the memory 44. The luminance characteristics LG1 and LB1 are also stored in the memory 44 in the same manner as the luminance characteristics LR1.

  In the multi-screen display device 1000, if the luminance adjustment process described later is not performed, there are the following problems. When the multi-screen display device 1000 is used for the first time, variations in luminance may occur in the images displayed by the projection type video display devices 100 due to manufacturing variations of the projection type video display devices 100.

  If the luminance adjustment process described later is not performed, each projection video display device 100 in accordance with the all-white video signal in a state where there is luminance variation, the entire screen 10 of the projection video display device 100. Is displayed in white. In this case, a luminance difference occurs between the screens 10 in the multi-screen 10A. As a result, the sense of unity of the video displayed on the multi-screen 10A is impaired.

  In addition, it is possible for the operator to perform an operation of adjusting the luminance of each projection display apparatus 100 by visual observation, a measuring instrument, or the like so that the luminance difference is suppressed. However, the operation is difficult and time consuming.

  Therefore, in the present embodiment, in order to solve the above problem, the brightness adjustment of each projection display apparatus 100 is appropriately and automatically performed in the following situations A and B. An example of the situation A is a situation in which any one of the plurality of projection video display devices 100 is changed by the operation of the external control device 6 by the user during the operation of the multi-screen display device 1000.

  In addition, an example of the situation B is a situation where, when the multi-screen display device 1000 is installed, the projection type video display devices 100 having different luminance modes are mixed. Hereinafter, a process for enabling such brightness adjustment will be described.

  In the present embodiment, multi-screen display apparatus 1000 performs a process for automatically adjusting the brightness in consideration of the brightness mode of each projection display apparatus 100 (hereinafter also referred to as brightness adjustment process). The brightness adjustment processing is mainly performed by the microcomputer 43 of the master device Ma and the slave devices Sb, Sc, Sd. Hereinafter, each of the slave devices Sb, Sc, Sd is also simply referred to as a slave device S.

  FIG. 5 is a flowchart of the brightness adjustment process. The brightness adjustment process is a process for automatically performing an adjustment for suppressing variation in brightness among the plurality of projection display apparatuses 100 in the above-described situation A or situation B, for example.

  Hereinafter, the brightness adjustment processing will be described with reference to FIG. First, the luminance adjustment process under condition A will be described. In condition A, as shown in FIG. 6A, the normal mode is set as the luminance mode in the master device Ma (projection-type image display device 100a) and slave device Sb (projection-type image display device 100b). And Further, it is assumed that the power saving mode is set as the luminance mode in the slave device Sc (projection type video display device 100c) and slave device Sd (projection type video display device 100d).

  In condition A, it is assumed that the luminance mode information α is stored in the memories 44 of the master device Ma and the slave device Sb. Further, it is assumed that the luminance mode information β is stored in each of the memories 44 of the slave devices Sc and Sd.

  In the following, the current value (control current value) of the control current of the light source 34R in the normal mode is also expressed as IRn_α. In the following, the current value (control current value) of the control current of the light source 34G in the normal mode is also expressed as IGn_α. In the following, the current value (control current value) of the control current of the light source 34B in the normal mode is also expressed as IBn_α.

  Note that “n” in each of IRn_α, IGn_α, and IBn_α is a natural number. The n corresponds to a number indicated by an ID number (for example, ID1) assigned to each projection display apparatus 100.

  Here, when n = 1, IRn_α, IGn_α, and IBn_α are control current values of the light sources 34R, 34G, and 34B included in the projection display apparatus 100a (master apparatus Ma), respectively. When n = 2, IRn_α, IGn_α, and IBn_α are control current values of the light sources 34R, 34G, and 34B included in the projection video display device 100b (slave device Sb), respectively.

  When n = 3, IRn_α, IGn_α, and IBn_α are control current values of the light sources 34R, 34G, and 34B included in the projection video display device 100c (slave device Sc), respectively. When n = 4, IRn_α, IGn_α, and IBn_α are control current values of the light sources 34R, 34G, and 34B included in the projection display apparatus 100d (slave device Sd), respectively.

  In the following, the current value (control current value) of the control current of the light source 34R in the power saving mode is also expressed as IRn_β. In the following, the current value (control current value) of the control current of the light source 34G in the power saving mode is also expressed as IGn_β. In the following, the current value (control current value) of the control current of the light source 34B in the power saving mode is also expressed as IBn_β. “N” in IRn_β, IGn_β, and IBn_β is the same as “n” in IRn_α, IGn_α, and IBn_α. Since IRn_β, IGn_β, and IBn_β are the same as IRn_α, IGn_α, and IBn_α described above, detailed description will not be repeated.

  Note that n shown in the values defined below is the same as “n” in IRn_α. That is, the value to which n = 1 is a value specified by the master device Ma, a calculated value, or the like. The value to which n = 2 is a value specified by the slave device Sb, a calculated value, or the like. The value to which n = 3 is a value specified by the slave device Sc, a calculated value, or the like. Further, the value to which n = 4 is a value specified by the slave device Sd, a calculated value, or the like.

  The brightness adjustment process in FIG. 5 includes steps S100M, S100N, and S100L. Step S100M is a step performed by the master device Ma. Step S100N is a step performed by the slave device S in the normal mode. Step S100L is a step performed by each slave device S in the power saving mode.

  Below, the process of step S100M, S100N, S100L in the above-mentioned condition A is demonstrated.

  First, in step S10, the microcomputer 43 of the master device Ma transmits a command for starting automatic adjustment to the slave devices Sb, Sc, Sd.

  Next, the microcomputer 43 of the master device Ma obtains the initial set value I0_α by reading the initial set value I0_α of each light source 34 corresponding to the normal mode from the memory 44 as the initial control current value (S21). ). Further, the microcomputer 43 of the slave device S in the normal mode reads the initial setting value I0_α of each light source 34 corresponding to the normal mode from the memory 44, thereby acquiring the initial setting value I0_α (S22N).

  Further, the microcomputer 43 of each slave device S in the power saving mode acquires the initial setting value I0_β by reading out the initial setting value I0_β of each light source 34 corresponding to the power saving mode from the memory 44 (S22L).

  Although the initial set values I0_α and I0_β are acquired from the memory 44, the present invention is not limited to this. The initial setting values I0_α and I0_β may be given to each slave device S together with the command transmitted from the master device Ma in step S10, for example.

  Next, the microcomputer 43 of each projection display apparatus 100 performs luminance specifying processing (S31, S32N, S32L). That is, the microcomputer 43 of each of the master device Ma and the slave devices Sb, Sc, Sd performs a luminance specifying process.

  In the luminance specifying process, the projection type video display device 100 can output the projection type video display device 100 using the luminance characteristic L stored in the memory 44 of the projection type video display device 100. This is a process for specifying a proper video brightness. That is, the microcomputer 43 of each of the master device Ma and the slave devices Sb, Sc, Sd specifies the video brightness by the brightness specifying process. Here, as an example, a process performed by the microcomputer 43 of the master device Ma in the luminance specifying process (S31) will be described.

  In the following, the luminance (R luminance) corresponding to I0_α and indicated by the luminance characteristic LR1 in FIG. 4A is also expressed as YR0n_α. Hereinafter, the luminance (G luminance) corresponding to I0_α and indicated by the luminance characteristic LG1 in FIG. 4B is also expressed as YG0n_α. In the following, the luminance (B luminance) corresponding to I0_α and indicated by the luminance characteristic LB1 in FIG. 4C is also expressed as YB0n_α.

  In the following, the luminance (R luminance) corresponding to I0_β and indicated by the luminance characteristic LR1 in FIG. 4A is also expressed as YR0n_β. Hereinafter, the luminance (G luminance) corresponding to I0_β and indicated by the luminance characteristic LG1 in FIG. 4B is also expressed as YG0n_β. In the following, the luminance (B luminance) corresponding to I0_β and indicated by the luminance characteristic LB1 in FIG. 4C is also expressed as YB0n_β.

  In the following description, the luminance corresponding to the control current specified from the luminance characteristic L for each set luminance mode is also referred to as characteristic luminance. That is, the characteristic luminance is the luminance specified from the luminance characteristic L. The characteristic luminance is image luminance that can be output by the projection type video display device 100 corresponding to the luminance mode set in the projection type video display device 100.

  In the luminance specifying process (S31), the microcomputer 43 uses the luminance characteristic L stored in the memory 44 to specify the characteristic luminance indicated by the luminance characteristic L corresponding to the control current value of each light source 34.

  At the time of step S31, IRn_α, IGn_α, and IBn_α, which are control current values of the light sources 34, are I0_α. Therefore, in the luminance specifying process, the microcomputer 43 specifies the characteristic luminance indicated by the luminance characteristic L corresponding to the initial control current value.

  More specifically, in the luminance specifying process (S31), the microcomputer 43 of the master device Ma uses the luminance characteristic LR1 stored in the memory 44 to indicate the luminance characteristic LR1 corresponding to the initial setting value I0_α. The characteristic luminance YR0n_α is specified. Similarly to the characteristic luminance YR0n_α, the microcomputer 43 uses the luminance characteristics LG1 and LB1 to identify the characteristic luminances YG0n_α and YB0n_α.

  In the luminance specifying process (S32N), the microcomputer 43 of the slave device S specifies the characteristic luminances YR0n_α, YG0n_α, YB0n_α in the slave device S as in step S31.

  In the luminance specifying process (S32L), the microcomputer 43 of each slave device S specifies the characteristic luminance YR0n_β indicated by the luminance characteristic LR1 corresponding to the initial setting value I0_β. Similarly to the luminance YR0n_β, the microcomputer 43 specifies the characteristic luminances YG0n_β and YB0n_β using the luminance characteristics LG1 and LB1.

  Next, in step S <b> 41, the microcomputer 43 of the master device Ma reads the luminance mode information α from the memory 44. The microcomputer 43 specifies that the luminance mode set in the projection video display device 100 (master device Ma) including the microcomputer 43 is the normal mode based on the luminance mode information α. In step S42N, the microcomputer 43 of the slave device S performs the same process as in step S41.

  In step S <b> 42 </ b> L, the microcomputer 43 of each slave device S reads the luminance mode information β from the memory 44. Based on the luminance mode information β, the microcomputer 43 specifies that the luminance mode set in the projection display apparatus 100 (slave apparatus S) including the microcomputer 43 is the power saving mode.

  Next, the microcomputer 43 of the master device Ma transmits a request instruction to the slave devices Sb, Sc, Sd (S51). The request instruction is an instruction for requesting luminance information and a mode identifier obtained by the microcomputer 43 of each slave device S. The luminance information is information indicating YR0n_s, YG0n_s, and YB0n_s.

  “N” in the YR0n_s, YG0n_s, and YB0n_s is any one of 2 to 4. Further, “s” in YR0n_s, YG0n_s, and YB0n_s is a mode identifier indicated by the luminance mode information read by the microcomputer 43 of the slave device S. For example, when the microcomputer 43 of the slave device S reads the luminance mode information α, “s” of the YR0n_s, YG0n_s, and YB0n_s is the mode identifier “α”.

  Then, the microcomputer 43 of each slave device S receives the request instruction (S52N, S52L).

  Next, the microcomputer 43 of the slave device S in the normal mode transmits luminance information indicating the identified YR0n_α, YG0n_α and YB0n_α and the mode identifier “α” to the master device Ma according to the request instruction (S62N). For example, the microcomputer 43 of the slave device Sb in the normal mode transmits luminance information indicating the specified YR02_α, YG02_α and YB02_α and the mode identifier “α” to the master device Ma in accordance with the request instruction.

  Further, the microcomputer 43 of each slave device S in the power saving mode transmits luminance information indicating the specified YR0n_β, YG0n_β, YB0n_β and the mode identifier “β” to the master device Ma according to the request instruction (S62L). For example, the microcomputer 43 of the slave device Sc in the power saving mode transmits luminance information indicating the identified YR03_β, YG03_β and YB03_β and the mode identifier “β” to the master device Ma in accordance with the request instruction.

  Then, the microcomputer 43 of the master device Ma receives a plurality of luminance information from the slave devices Sb, Sc, Sd (S61).

  In step S70, a target luminance calculation process is performed. In the target luminance calculation process, the microcomputer 43 of the master device Ma calculates the target luminance for each luminance mode based on the characteristic luminance of the master device Ma and the characteristic luminance of each slave device S. That is, the microcomputer 43 of the master device Ma is a calculation unit that calculates the target luminance.

  The characteristic luminance of the master device Ma is characteristic luminance YR0n_α, YG0n_α, YB0n_α when n = 1. The characteristic luminance of the slave device S is characteristic luminance YR0n_s, YG0n_s, YB0n_s. In YR0n_s, YG0n_s, and YB0n_s, n is any one of 2 to 4, and s is α or β that is a mode identifier.

  More specifically, in the target luminance calculation process, the microcomputer 43 of the master device Ma sets the characteristic luminance of the master device Ma, the set luminance mode of the master device Ma, the characteristic luminance of each slave device S, and the setting of each slave device S. Based on the brightness mode, the target brightness is calculated for each brightness mode (set brightness mode).

  The target luminance is the target luminance of each projection display apparatus 100 in the same luminance mode. That is, the target luminance is the luminance common to each of the plurality of projection video display devices 100 in the same luminance mode.

  Hereinafter, the target luminance calculation processing will be described in detail with specific examples. In the target luminance calculation process, first, the microcomputer 43 of the master device Ma grasps the set luminance mode of the slave devices Sb, Sc, Sd based on the mode identifier indicated by the luminance information received from each slave device S.

  Here, the set brightness mode of the slave device Sb is the normal mode, and the set brightness mode of the slave devices Sc and Sd is the power saving mode. The set brightness mode of the master device Ma is the normal mode.

  Hereinafter, the group to which the projection display apparatus 100 whose set luminance mode is the normal mode belongs is also referred to as a group α. In the following, the group to which the projection display apparatus 100 whose set luminance mode is the power saving mode belongs is also referred to as a group β.

  In the following, the characteristic luminance of the projection display apparatus 100 belonging to the group α is also expressed as Y_α. In the following, the characteristic luminance of the projection display apparatus 100 belonging to the group β is also expressed as Y_β.

  The microcomputer 43 of the master device Ma determines the characteristic luminances YR01_α, YG01_α, YB01_α of the master device Ma belonging to the group α and the characteristic luminances YR02_α, YG02_α, YB02_α received from the slave device Sb as the characteristic luminance Y_α.

  Further, the microcomputer 43 of the master device Ma determines the characteristic luminances YR0n_β, YG0n_β, YB0n_β received from the slave devices Sc and Sd belonging to the group β as the characteristic luminance Y_β. N in the characteristic luminances YR0n_β, YG0n_β, and YB0n_β is 3 or 4.

  Next, the microcomputer 43 of the master device Ma calculates the same target luminance for each set luminance mode in order to reduce the luminance variation between the screens 10 of the projection video display devices 100 in the same luminance mode. To do. As an example, the microcomputer 43 calculates a different target luminance for each of the normal mode and the power saving mode.

  In the following, the target luminances of R, G, and B in the projection display apparatus 100 belonging to the group α are also expressed as target luminances YRT_α, YGT_α, and YBT_α, respectively. The target luminance YRT_α is the R target luminance. The target luminance YGT_α is the G target luminance. The target luminance YBT_α is the B target luminance.

  In the following, the target luminances of R, G, and B in the projection display apparatus 100 belonging to the group β are also expressed as target luminances YRT_β, YGT_β, and YBT_β, respectively. The target luminance YRT_β is the R target luminance. The target luminance YGT_β is the G target luminance. The target luminance YBT_β is the B target luminance.

  In the following, each of YRT_α and YRT_β is also expressed as YRT_s. In the following, each of YGT_α and YGT_β is also expressed as YGT_s. In the following, each of YBT_α and YBT_β is also expressed as YBT_s. “S” in YRT_s, YGT_s, and YBT_s is the mode identifier α or β.

  First, for the group α corresponding to the normal mode, the microcomputer 43 of the master device Ma uses, as the target luminance, the characteristic luminance Y_α indicating the smallest value among the plurality of characteristic luminances Y_α in each of R, G, and B. calculate. The plurality of characteristic luminances Y_α are characteristic luminances YR01_α, YG01_α, YB01_α, YR02_α, YG02_α, and YB02_α.

  For example, the target luminance YRT_α corresponding to R is calculated by YRT_α = Min (YR01_α, YR02_α). YRT_α = Min (YR01_α, YR02_α) is an equation for calculating the characteristic luminance indicating the smallest value among YR01_α and YR02_α as the target luminance YRT_α.

  Further, the target luminance YGT_α corresponding to G is calculated by YGT_α = Min (YG01_α, YG02_α). Further, the target luminance YBT_α corresponding to B is calculated by YBT_α = Min (YB01_α, YB02_α).

  The reason why the characteristic luminance Y_α showing the smallest value among the plurality of characteristic luminances Y_α is calculated as the target luminance will be described below. Here, it is assumed that the target luminance is characteristic luminance Y_α that indicates a value other than the smallest value. In this case, the video brightness of the projection display apparatus 100 with the lowest video brightness cannot satisfy the provisional target brightness. For this reason, the luminance variation appears remarkably. Therefore, the target luminance of each projection display apparatus 100 belonging to the group α is necessarily matched with the characteristic luminance indicating the minimum value.

  Next, for the group β corresponding to the power saving mode, the microcomputer 43 of the master device Ma sets the characteristic luminance Y_β indicating the largest value among the plurality of characteristic luminances Y_β in each of R, G, and B to the target Calculated as luminance. The plurality of characteristic luminances Y_β are characteristic luminances YR03_β, YG03_β, YB03_β, YR04_β, YG04_β, and YB04_β.

  The target luminance YRT_β corresponding to R is calculated by YRT_β = Max (YR03_β, YR04_β). YRT_β = Max (YR03_β, YR04_β) is an expression for calculating the target luminance YRT_β having the highest value among YR03_β and YR04_β. Further, the target brightness YGT_β corresponding to G is calculated by YGT_β = Max (YG03_β, YG04_β). Further, the target luminance YBT_β corresponding to B is calculated by YBT_β = Max (YB03_β, YB04_β).

  The reason why the characteristic luminance Y_β showing the largest value among the plurality of characteristic luminances Y_β is calculated as the target luminance will be described below. This is because the initial current value in the power saving mode is set to a value that cannot be lowered below the current value due to restrictions on the electronic circuit that constitutes the projection display apparatus 100. Therefore, it is necessary to match the target luminance of each projection display apparatus 100 belonging to the group β with the characteristic luminance indicating the highest value.

  Thus, the target brightness calculation process ends.

  Next, in step S81, target luminance transmission processing is performed. In the target luminance transmission process, the microcomputer 43 of the master device Ma transmits the calculated target luminances YRT_s, YGT_s, YBT_s to the slave devices S belonging to any of the groups α, β according to the mode identifiers α, β.

  For example, the microcomputer 43 transmits the target luminances YRT_α, YGT_α, YBT_α to the slave devices Sb belonging to the group α. Further, the microcomputer 43 transmits the target luminances YRT_β, YGT_β, and YBT_β to the slave devices Sc and Sd belonging to the group β.

  The microcomputer 43 of each slave device S receives the target luminances YRT_s, YGT_s, YBT_s (S82N, S82L). For example, the microcomputer 43 of the slave device Sc receives the target luminances YRT_β, YGT_β, YBT_β (S82L).

  Hereinafter, the control current value indicated by the luminance characteristic LR1 in FIG. 4A corresponding to the target luminance YRT_α is also expressed as IRTn_α. In the following, the control current value indicated by the luminance characteristic LG1 in FIG. 4B corresponding to the target luminance YGT_α is also expressed as IGTn_α. In the following, the control current value indicated by the luminance characteristic LB1 in FIG. 4C corresponding to the target luminance YBT_α is also expressed as IBTn_α.

  In the following, the control current value indicated by the luminance characteristic LR1 in FIG. 4A corresponding to the target luminance YRT_β is also expressed as IRTn_β. In the following, the control current value indicated by the luminance characteristic LG1 in FIG. 4B corresponding to the target luminance YGT_β is also expressed as IGTn_β. In the following, the control current value indicated by the luminance characteristic LB1 in FIG. 4C corresponding to the target luminance YBT_β is also expressed as IBTn_β.

  In the following, each of IRTn_α and IRTn_β is also expressed as IRTn_s. In the following, each of IGTn_α and IGTn_β is also expressed as IGTn_s. In the following, each of IBTn_α and IBTn_β is also expressed as IBTn_s.

  Since “n” in IRTn_s, IGTn_s, and IBTn_s is the same as “n” in the above-described IRn_α, detailed description will not be repeated. “S” in IRTn_s, IGTn_s, and IBTn_s is the mode identifier α or β.

  Next, the microcomputer 43 of each projection display apparatus 100 performs a control current specifying process (S91, S92N, S92L). That is, the microcomputer 43 of each of the master device Ma and the slave devices Sb, Sc, Sd performs a control current specifying process.

  The control current specifying process is a process in which the microcomputer 43 of each projection display apparatus 100 uses the luminance characteristic L stored in the memory 44 of the projection display apparatus 100 to specify the control current value. . More specifically, the control current specifying process is calculated by each projection display apparatus 100 using the luminance characteristic L and corresponding to the brightness mode set in the projection display apparatus 100. This is processing for specifying a control current value that is a value of the control current corresponding to the target luminance. Specifically, the control current specifying process is a process in which each projection display apparatus 100 uses the brightness characteristic L and the received target brightness to specify a control current value corresponding to the target brightness.

  Here, as an example, a process performed by the microcomputer 43 of the master device Ma in the control current specifying process (S91) will be described. In the control current specifying process (S91), the microcomputer 43 uses the brightness characteristic LR1 stored in the memory 44 to specify the control current value IRT1_α indicated by the brightness characteristic LR1 corresponding to the target brightness YRT_α. Similarly to the control current value IRT1_α, the microcomputer 43 specifies the control current values IGT1_α and IBT1_α using the luminance characteristics LG1 and LB1.

  In the control current specifying process (S92N), the microcomputer 43 of the slave device Sb in the normal mode specifies IRT2_α, IGT2_α, and IBT2_α in the slave device Sb as in step S91.

  In the control current specifying process (S92L), the microcomputer 43 of each slave device S in the power saving mode specifies IRTn_β, IGTn_β, and IBTn_β in each slave device S in the same manner as in step S91. “N” in IGTn_β and IBTn_β is 3 or 4.

  Next, the microcomputer 43 of each projection display apparatus 100 performs a current control process (S93, S94N, S94L). That is, the microcomputer 43 of each of the master device Ma and the slave devices Sb, Sc, Sd performs current control processing.

  The current control process is a process in which each projection display apparatus 100 supplies a current indicating the specified control current value to the light source 34 of the projection display apparatus 100.

  Here, as an example, a process performed by the microcomputer 43 of the master device Ma in the current control process (S93) will be described. In the current control process (S93), the microcomputer 43 controls the light source driver 35 so that the target current indicating the specified control current value IRT1_α is supplied to the light source 34R. The specified control current value IRT1_α is a target control current value, that is, a target control current value.

  Further, the microcomputer 43 controls the light source driver 35 so that a target current indicating the specified control current value IGT1_α is supplied to the light source 34G. In addition, the microcomputer 43 controls the light source driver 35 so that a target current indicating the specified control current value IBT1_α is supplied to the light source 34B.

  In the current control process (S94N), the microcomputer 43 of the slave device Sb controls the light source driver 35 as in step S93.

  In the current control process (S94L), the microcomputer 43 of each slave device S controls the light source driver 35 as in step S93. Hereinafter, as an example, the processing of the slave device Sc will be described.

  The microcomputer 43 of the slave device Sc controls the light source driver 35 so that a target current indicating the specified control current value IRT1_β is supplied to the light source 34R. Further, the microcomputer 43 controls the light source driver 35 so that a target current indicating the specified control current value IGT1_β is supplied to the light source 34G. Further, the microcomputer 43 controls the light source driver 35 so that a target current indicating the specified control current value IBT1_β is supplied to the light source 34B.

  Through the above-described current control processing (S93, S94N, S94L), each of the master device Ma and the slave devices Sb, Sc, Sd is based on the calculated target brightness and the control current to be supplied to each light source 34 of its own device. To change. Then, Steps S100M, S100N, and S100L are finished, and the brightness adjustment process in FIG. 5 is finished.

  In the above description, as shown in FIG. 6A, the processing in the case where the normal mode and the power saving mode are mixed in the luminance mode set in each projection video display device has been described. In actual operation of the multi-screen display device 1000, as shown in FIG. 6B or FIG. 6C, the plurality of luminance modes respectively set in the plurality of projection video display devices 100 are set to the same luminance mode. In many cases, the brightness modes of all the plurality of projection type video display devices 100 are switched and operated.

  Here, as shown in FIG. 6B, it is assumed that all the luminance modes of the plurality of projection type video display devices 100 are the power saving modes. In this case, each of the slave devices Sb, Sc, Sd transmits the luminance value and the mode identifier “β” in the power saving mode to the master device Ma in step S62L of FIG. Then, the brightness adjustment of each projection display apparatus 100 is performed in steps after step S70.

  Further, as shown in FIG. 6C, it is assumed that all the luminance modes of the plurality of projection type video display apparatuses 100 are the normal modes. In this case, each of the slave devices Sb, Sc, Sd transmits the luminance value in the normal mode and the mode identifier “α” to the master device Ma in step S62N of FIG. Then, the brightness adjustment of each projection display apparatus 100 is performed in steps after step S70.

  As described above, according to the present embodiment, the microcomputer 43 calculates the target luminance for each luminance mode. Each projection video display device 100 specifies a target control current value corresponding to the target luminance calculated corresponding to the luminance mode set in the projection video display device 100. Each projection display apparatus 100 supplies a current indicating the specified control current value to the light source 34 of the projection display apparatus 100.

  Thereby, the light source suitable for the luminance mode can be controlled. Therefore, it is possible to suppress variations in luminance among the projection type video display devices in which the same luminance mode is set.

  Further, in the present embodiment, grouping is performed for each luminance mode in the multi-screen display device 1000 even when the projection display device 100 having different luminance modes coexists in the multi-screen display device 1000. Then, the master device Ma calculates the optimum target luminance by transmitting and receiving the target luminance to and from the slave devices S of each group.

  Therefore, in the multi-screen display device 1000, even when the projection type video display devices 100 having different luminance modes coexist, variation in luminance among the projection type video display devices 100 can be suppressed for each group. That is, it is possible to suppress variation in luminance between the projection type video display devices 100 in the same luminance mode. For example, also in the above-described situations A and B, it is possible to suppress variations in luminance between the projection type video display devices 100 in the same luminance mode. As a result, the sense of unity of the video displayed on the multi-screen display device 1000 can be improved.

  Further, for example, as shown in FIGS. 6A, 6 </ b> B, and 6 </ b> C, even if the setting pattern of the luminance mode is switched, the master device Ma is assigned to the group corresponding to the luminance mode for each luminance mode. The optimum value of the target luminance of the projection display apparatus 100 to which it belongs is updated. Thereby, the output luminance of the multi-screen display device 1000 can always be kept uniform.

  In general, in a projection display apparatus using a semiconductor light source, output luminance and power consumption can be adjusted by a current supplied to the semiconductor light source. Therefore, in a multi-screen display device, for example, there may be a case where a group of projection video display devices that display with high brightness and a group that displays with low brightness are mixed to save power.

  That is, when operating each projection type video display apparatus in groups, it is necessary to calculate an optimum target luminance for each group. In Related Technology A, it is not possible to calculate target luminance corresponding to a group and perform luminance adjustment of a multi-screen display device corresponding to the group.

  On the other hand, since multi-screen display apparatus 1000 according to the present embodiment has the above-described configuration, it is possible to perform brightness adjustment of the multi-screen display apparatus corresponding to the group.

  In the present embodiment, the luminance mode set for each projection video display device 100 is two types, the normal mode and the power saving mode, but is not limited to this. There may be three or more luminance modes. In this case, the microcomputer 43 is configured to calculate a target luminance that achieves the purpose of each luminance mode. Therefore, a configuration in which there are different types or numbers of luminance modes from the normal mode and the power saving mode is also within the scope of the present invention.

  This is because the gist of the present invention is to match the luminance between the same projection type video display devices 100. In order to realize this, the microcomputer 43 groups the luminance values that can be output at that time of the plurality of projection type video display devices 100 for each luminance mode, and sets the target luminance for each group according to the purpose of the luminance mode. calculate. Each projection display apparatus 100 adjusts the control current of the light source 34 using the target luminance corresponding to its own luminance mode.

  In the present embodiment, the microcomputer 43 of the master device Ma calculates the target luminance. However, the present invention is not limited to this. The external control device 6 that communicates with each projection display apparatus 100 may calculate the target luminance instead of the microcomputer 43 of the master device Ma. That is, the external control device 6 is a calculation device that calculates the target luminance. In this case, the external control device 6 performs each process in step S100M of FIG. 5 instead of the microcomputer 43 of the master device Ma.

  That is, the external control device 6 calculates the target luminance for each luminance mode using the luminance information obtained from each slave device S. Then, the external control device 6 transmits the calculated target luminance corresponding to each luminance mode to the slave device S corresponding to each luminance mode.

  As described above, the external controller 6 calculates the target luminance instead of the microcomputer 43, and the following effects are obtained. Specifically, since the external control device 6 calculates the target luminance, it is not necessary to provide each projection type video display device 100 constituting the multi-screen display device 1000 with a function for calculating the target luminance.

  Therefore, in the already installed multi-screen display device 1000, the present invention is cheaper than the case where the projection type video display device 100 is modified and the projection type video display device 100 has a function of calculating the target luminance. It can be realized.

<Embodiment 2>
In the first embodiment, the processing for suppressing the luminance variation between the plurality of projection video display devices 100 in the same luminance mode has been described. Here, the chromaticity value (chromaticity characteristic) of the LED corresponding to the control current value is different for each LED due to manufacturing variation or the like. Moreover, in the first embodiment, the control current value is not calculated in consideration of chromaticity. Therefore, there is a possibility that the chromaticity varies somewhat in the multi-screen display device 1000 according to the first embodiment.

  Therefore, in the multi-screen display device according to the present embodiment, processing is performed that can suppress not only luminance variations but also chromaticity variations. The multi-screen display device according to the present embodiment is the multi-screen display device 1000 of FIG. Hereinafter, the processing different from that of the first embodiment will be mainly described.

  In the present embodiment, the microcomputer 43 adjusts the chromaticity characteristics and the luminance and chromaticity of each of R, G, and B used by the video processing circuit 42 in addition to the luminance characteristics LR1, LG1, LB1 described above. Various control data further including image quality adjustment values for the image are stored in the memory 44 in advance. The chromaticity characteristic is a characteristic indicating chromaticity corresponding to each control current value of the light sources 34R, 34G, and 34B. A part of the image quality adjustment value is, for example, the correction coefficient of Equation 1 described above. The microcomputer 43 reads various control data in the memory 44 as necessary.

  Hereinafter, the chromaticity of an image displayed by the projection display apparatus 100 using light emitted from the light source 34 is also referred to as image chromaticity. The video chromaticity is the chromaticity of the video displayed on the screen 10.

  In the following, the control current values IRTn_s, IGTn_s, and IBTn_s are also simply referred to as control current values IRT, IGT, and IBT, respectively.

  In the present embodiment, each projection display apparatus 100 performs the aforementioned characteristic calculation process before being shipped from the factory. Thus, the memory 44 of each projection type video display device 100 stores the luminance characteristics LR1, LG1, LB1 corresponding to the projection type video display device 100.

  In addition, each projection display apparatus 100 further performs a characteristic calculation step A before being shipped from the factory. In the characteristic calculation step A, the projection display apparatus 100 gradually changes the control current supplied to each light source 34 for each of R, G, and B, and measures the image chromaticity at that time. Thereby, the projection display apparatus 100 calculates chromaticity characteristics indicating the relationship between the control current of the light source 34 and the video chromaticity corresponding to the control current.

  FIG. 7 is a diagram illustrating an example of chromaticity characteristics. Specifically, FIG. 7 shows chromaticity coordinates of an xy chromaticity diagram in the CIE-XYZ color system.

  In FIG. 7, x and y indicate chromaticity. FIG. 7 shows chromaticity characteristics CR1, CG1, and CB1. The chromaticity characteristic CR1 is a characteristic indicating chromaticity corresponding to the control current value IRT. The chromaticity characteristic CG1 is a characteristic indicating chromaticity corresponding to the control current value IGT. The chromaticity characteristic CB1 is a characteristic indicating chromaticity corresponding to the control current value IBT. That is, each of the chromaticity characteristics CR1, CG1, and CB1 is a current chromaticity characteristic indicating the chromaticity corresponding to the control current value.

  Specifically, in the characteristic calculation step A, the projection display apparatus 100 calculates chromaticity characteristics CR1, CG1, and CB1. Then, the projection display apparatus 100 stores the chromaticity characteristics CR1, CG1, and CB1 in the memory 44 of the projection display apparatus 100. That is, the memory 44 of each projection display apparatus 100 stores chromaticity characteristics CR1, CG1, and CB1 corresponding to the projection display apparatus 100. Hereinafter, each of the chromaticity characteristics CR1, CG1, and CB1 is also simply referred to as a chromaticity characteristic C.

  Next, the multi-screen display device 1000 performs processing for automatically adjusting the luminance and chromaticity in consideration of the luminance mode of each projection video display device 100 (hereinafter also referred to as luminance chromaticity adjustment processing). Do. The luminance / chromaticity adjustment processing is processing for suppressing variations in luminance and chromaticity between the projection type video display devices 100 in the same luminance mode. The luminance / chromaticity adjustment processing is performed, for example, when the multi-screen display device 1000 is used for the first time. The luminance / chromaticity adjustment processing is performed, for example, when the multi-screen display device 1000 is installed.

  FIG. 8 is a flowchart of the luminance / chromaticity adjustment processing. In FIG. 8, the processing with the same step number as the step number of FIG. 5 is performed in the same manner as the processing described in the first embodiment, and therefore detailed description will not be repeated. Hereinafter, a description will be given focusing on differences from the first embodiment.

  First, the luminance / chromaticity adjustment processing under the above-described condition A will be described. Under the condition A, as described above, as shown in FIG. 6A, the master device Ma (projection-type image display device 100a) and slave device Sb (projection-type image display device 100b) have the normal mode as the luminance mode. Is set. Further, it is assumed that the power saving mode is set as the luminance mode in the slave device Sc (projection type video display device 100c) and slave device Sd (projection type video display device 100d).

  The brightness adjustment process in FIG. 8 includes steps S102M, S102N, and S102L. Step S102M is a step performed by the master device Ma. Step S102N is a step performed by the slave device S in the normal mode. Step S102L is a step performed by each slave device S in the power saving mode.

  First, in steps S10 to S93, steps S22N to S94N, and steps S22L to S94N in FIG. 8, processing similar to that in the first embodiment is performed.

  In the following, the chromaticity values indicated by the chromaticity characteristic CR1 in FIG. 7 corresponding to the control current value IRTn_α are also expressed as xR0n_α and yR0n_α. Hereinafter, the chromaticity values indicated by the chromaticity characteristics CG1 corresponding to the control current value IGTn_α are also expressed as xG0n_α and yG0n_α. In the following, the chromaticity values indicated by the chromaticity characteristic CB1 corresponding to the control current value IBTn_α are also expressed as xB0n_α and yB0n_α.

  In the following description, the chromaticity values indicated by the chromaticity characteristic CR1 corresponding to the control current value IRTn_β described above are also expressed as xR0n_β and yR0n_β. In the following, the chromaticity values indicated by the chromaticity characteristics CG1 corresponding to the control current value IGTn_α are also expressed as xG0n_β and yG0n_β. In the following, the chromaticity values indicated by the chromaticity characteristic CB1 corresponding to the control current value IBTn_α are also expressed as xB0n_β and yB0n_β.

  In the following, each of xR0n_α and xR0n_β is also expressed as xR0n_s. In the following, each of xG0n_α and xG0n_β is also expressed as xG0n_s. In the following, each of xB0n_α and xB0n_β is also expressed as xB0n_s.

  Hereinafter, each of yR0n_α and yR0n_β is also expressed as yR0n_s. In the following, each of yG0n_α and yG0n_β is also expressed as yG0n_s. In the following, each of yB0n_α and yB0n_β is also expressed as yB0n_s.

  Since “n” in xR0n_s, xG0n_s, xB0n_s, yR0n_s, yG0n_s, and yB0n_s is the same as “n” in IRn_α described above, detailed description will not be repeated. “s” in xR0n_s, xG0n_s, xB0n_s, yR0n_s, yG0n_s and yB0n_s is the mode identifier α or β.

  Next, the microcomputer 43 of each projection display apparatus 100 performs chromaticity identification processing (S120, S120N, S120L). That is, the microcomputer 43 of each of the master device Ma and the slave devices Sb, Sc, Sd performs chromaticity specifying processing.

  The chromaticity specifying process is a process in which the microcomputer 43 of each projection video display device 100 uses the chromaticity characteristic C stored in the memory 44 of the projection video display device 100 to specify the chromaticity. .

  Here, as an example, a process performed by the microcomputer 43 of the master device Ma in the chromaticity specifying process (S120) will be described. In the chromaticity specifying process (S120), the microcomputer 43 uses the chromaticity characteristic CR1 stored in the memory 44 to obtain the chromaticity values xR0n_α and yR0n_α indicated by the chromaticity characteristic CR1 corresponding to the control current value IRTn_α. Identify. Similarly to the chromaticity values xR0n_α and yR0n_α, the microcomputer 43 uses the chromaticity characteristics CG1 and CB1 luminance characteristics LG1 and LB1 to specify the chromaticity values xG0n_α, yG0n_α, xB0n_α and yB0n_α.

  In the chromaticity specifying process (S120N), the microcomputer 43 of the slave device Sb in the normal mode specifies the chromaticity values xG02_α, yG02_α, xB02_α, yB02_α in the slave device Sb as in step S120.

  In the chromaticity specifying process (S120L), the microcomputer 43 of each slave device S in the power saving mode, similarly to step S120, the chromaticity values xR0n_β, yR0n_β, xG0n_β, yG0n_β, xB0n_β, yB0n_β in each slave device S. Is identified. “N” in the chromaticity values xR0n_β, yR0n_β, xG0n_β, yG0n_β, xB0n_β, and yB0n_β is 3 or 4.

  Next, the microcomputer 43 of the master device Ma transmits a request instruction A to the slave devices Sb, Sc, Sd (S121). The request instruction A is an instruction for requesting the chromaticity information and the mode identifier obtained by the microcomputer 43 of each slave device S. The request instruction A is an instruction for requesting the chromaticity information and the mode identifier obtained by the microcomputer 43 of each slave device S. The chromaticity information is information indicating the chromaticity values xR0n_s, xG0n_s, xB0n_s, yR0n_s, yG0n_s, yB0n_s corresponding to the set luminance mode of each slave device S.

  Then, the microcomputer 43 of each slave device S receives the request instruction A (S121N, S121L).

  Next, in accordance with the request instruction A, the microcomputer 43 of the slave device S in the normal mode masters chromaticity information indicating the specified chromaticity values xR0n_α, xG0n_α, xB0n_α, yR0n_α, yG0n_α, yB0n_α and the mode identifier “α”. The data is transmitted to the device Ma (S122N).

  Further, the microcomputer 43 of each slave device S in the power saving mode, according to the request instruction A, includes chromaticity information indicating the specified chromaticity values xR0n_β, xG0n_β, xB0n_β, yR0n_β, yG0n_β, yB0n_β and the mode identifier “β”. The data is transmitted to the master device Ma (S122L). For example, according to the request instruction A, the microcomputer 43 of the slave device Sc in the power saving mode masters chromaticity information indicating the specified chromaticity values xR03_β, xG03_β, xB03_β, yR03_β, yG03_β, yB03_β and the mode identifier “β”. Transmit to the device Ma.

  Then, the microcomputer 43 of the master device Ma receives a plurality of chromaticity information from the slave devices Sb, Sc, Sd (S122).

  Hereinafter, the chromaticity value (chromaticity) corresponding to the control current value specified by the microcomputer 43 in the aforementioned control current specifying process is also referred to as specific chromaticity. The specific chromaticity is the chromaticity specified by the microcomputer 43 of the master device Ma or the slave device S in the chromaticity specifying process described above. That is, the specific chromaticity is a chromaticity value (chromaticity) corresponding to the control current values IRTn_s, IGTn_s, and IBTn_s specified in the control current specifying process. The specific chromaticity is xR0n_s, xG0n_s, xB0n_s, yR0n_s, yG0n_s, and yB0n_s.

  In step S123, target chromaticity calculation processing is performed. Although details will be described later in the target chromaticity calculation processing, the microcomputer 43 of the master device Ma determines the specific chromaticity specified by the master device Ma, the luminance mode set in the master device Ma, and each slave device S. Based on the specified specific chromaticity and the luminance mode set in each slave device S, the target chromaticity is calculated for each luminance mode. The target chromaticity is a target chromaticity of each projection display apparatus 100 in the same luminance mode. That is, the target chromaticity is a common chromaticity that can be reproduced by each of the plurality of projection display apparatuses 100 having the same luminance mode.

  In the following, in the chromaticity coordinates of the xy chromaticity diagram, a triangle having chromaticity values xR01_α, yR01_α, chromaticity values xG01_α, yG01_α, and chromaticity values xB01_α, yB01_α as vertices is also expressed as chromaticity characteristic CL1. (See FIG. 9A). The chromaticity characteristic CL1 is configured by each chromaticity value specified by the master device Ma.

  Further, in the following, in the chromaticity coordinates of the xy chromaticity diagram, a triangle having apexes of the chromaticity values xR02_α, yR02_α, the chromaticity values xG02_α, yG02_α, and the chromaticity values xB02_α, yB02_α is represented by the chromaticity characteristic CL2. (Refer to FIG. 9A). The chromaticity characteristic CL2 is configured by each chromaticity value specified by the slave device Sb.

  In the following, in the chromaticity coordinates of the xy chromaticity diagram, a triangle having chromaticity values xR03_β, yR03_β, chromaticity values xG03_β, yG03_β, and chromaticity values xB03_β, yB03_β as vertices is represented as chromaticity characteristics CL3. (Refer to FIG. 9B). The chromaticity characteristic CL3 is configured by each chromaticity value specified by the slave device Sc.

  Also, in the following, in the chromaticity coordinates of the xy chromaticity diagram, a triangle having the chromaticity values xR04_β, yR04_β, the chromaticity values xG04_β, yG04_β, and the chromaticity values xB04_β, yB04_β as vertices is represented by the chromaticity characteristic CL4. (Refer to FIG. 9B). The chromaticity characteristic CL4 is configured by each chromaticity value specified by the slave device Sd. Hereinafter, each of the chromaticity characteristics CL1, CL2, CL3, and CL4 is also simply referred to as a chromaticity characteristic CL.

  In the following, the target chromaticity corresponding to the normal mode (group α) is also expressed as target chromaticity xRT_α, yRT_α, xGT_α, yGT_α, xBT_α, yBT_α. In the following, the target chromaticity corresponding to the power saving mode (group β) is also expressed as target chromaticity xRT_β, yRT_β, xGT_β, yGT_β, xBT_β, and yBT_β.

  In the following, each of the target chromaticities xRT_α and xRT_β is also expressed as xRT_s. In the following, each of the target chromaticities xGT_α and xGT_β is also expressed as xGT_s. In the following, each of the target chromaticities xBT_α and xBT_β is also expressed as xBT_s.

  In the following, each of the target chromaticities yRT_α and yRT_β is also expressed as yRT_s. In the following description, each of the target chromaticities yGT_α and yGT_β is also expressed as yGT_s. In the following description, each of the target chromaticities yBT_α and yBT_β is also expressed as yBT_s.

  “s” in xRT_s, xGT_s, xBT_s, yRT_s, yGT_s, and yBT_s is the mode identifier α or β.

  In the following, the target chromaticity corresponding to the normal mode is also referred to as normal target chromaticity. Hereinafter, the target chromaticity corresponding to the power saving mode is also referred to as a power saving target chromaticity.

  Next, a method for calculating the target chromaticity for each luminance mode in the target chromaticity calculation processing will be described. FIG. 9 is a diagram for explaining a method for calculating the target chromaticity. FIG. 9 is a diagram showing each chromaticity characteristic CL in the chromaticity coordinates of the xy chromaticity diagram. FIG. 9A shows chromaticity characteristics CL1 and CL2. FIG. 9B shows chromaticity characteristics CL3 and CL4.

  In the target chromaticity calculation process, the microcomputer 43 of the master device Ma determines the chromaticity of three points within the area where a plurality of triangles (chromaticity characteristics CL) overlap and close to the vertex of each triangle as the target color. Calculate as degrees. In other words, the chromaticity of the point closest to the white chromaticity among the one or more points where the chromaticity characteristics CL intersect in each of the three vertexes of each chromaticity characteristic CL (triangle) is calculated as the target chromaticity.

  First, calculation of normal target chromaticity will be described. Referring to FIG. 9A, the microcomputer 43 determines the chromaticity at the point where the chromaticity characteristics CL1 and CL2 intersect in the vicinity of the three vertices of the chromaticity characteristics CL1 and CL2, respectively, as the target chromaticity xRT_α, It is calculated as yRT_α, target chromaticity xGT_α, yGT_α, target chromaticity xBT_α, yBT_α.

  For example, the microcomputer 43 sets the chromaticity at the point where the chromaticity characteristics CL1 and CL2 intersect in the vicinity of the vertex close to R (red) of each of the chromaticity characteristics CL1 and CL2 to the target chromaticity (xRT_α) that is the normal target chromaticity. , YRT_α).

  Next, calculation of the power saving target chromaticity will be described. Referring to FIG. 9B, the microcomputer 43 determines the chromaticity at the point where the chromaticity characteristics CL3 and CL4 intersect in the vicinity of the three vertices of the chromaticity characteristics CL3 and CL4, as the target chromaticity xRT_β, It is calculated as yRT_β, target chromaticity xGT_β, yGT_β, target chromaticity xBT_β, yBT_β.

  For example, the microcomputer 43 sets the chromaticity at the point where the chromaticity characteristics CL3 and CL4 intersect near the vertex close to R (red) of each of the chromaticity characteristics CL3 and CL4 as the target chromaticity (the power saving target chromaticity ( xRT_β, yRT_β). As described above, the target chromaticity is calculated for each luminance mode.

  Next, in step S124, target chromaticity transmission processing is performed. In the target chromaticity transmission process, the microcomputer 43 of the master device Ma sends the calculated target chromaticity xRT_s, xGT_s, xBT_s, yRT_s, yGT_s, yBT_s to the slaves belonging to any of the groups α and β according to the mode identifiers α and β. Transmit to device S.

  For example, the microcomputer 43 transmits the target chromaticities xRT_α, xGT_α, xBT_α, yRT_α, yGT_α, yBT_α to the slave devices Sb belonging to the group α. Further, the microcomputer 43 transmits the target chromaticities xRT_β, xGT_β, xBT_β, yRT_β, yGT_β, yBT_β to the slave devices Sc and Sd belonging to the group β.

  The microcomputer 43 of each slave device S receives the target chromaticities xRT_s, xGT_s, xBT_s, yRT_s, yGT_s, yBT_s (S124N, S124L). The microcomputer 43 of the slave device Sb receives the target chromaticities xRT_α, xGT_α, xBT_α, yRT_α, yGT_α, yBT_α (S124N). In addition, the microcomputer 43 of each slave device S belonging to the group β receives the target chromaticities xRT_β, xGT_β, xBT_β, yRT_β, yGT_β, yBT_β (S124L).

  Next, the microcomputer 43 of each projection display apparatus 100 performs the arithmetic process K (S125, S125N, S125L). That is, the microcomputer 43 of each of the master device Ma and the slave devices Sb, Sc, Sd performs the arithmetic process K.

  In the following, the stimulus values corresponding to the group α and corresponding to R are also expressed as XR0n_α and ZR0n_α. In the following, the stimulus values corresponding to the group α and corresponding to G are also expressed as XG0n_α and ZG0n_α. In the following, the stimulus values corresponding to the group α and corresponding to B are also expressed as XB0n_α and ZB0n_α.

  In the following, the stimulus values corresponding to the group β and corresponding to R are also expressed as XR0n_β and ZR0n_β. In the following, the stimulus values corresponding to the group β and corresponding to G are also expressed as XG0n_β and ZG0n_β. In the following, the stimulus values corresponding to group β and corresponding to B are also expressed as XB0n_β and ZB0n_β.

  In the following, each of XR0n_α and XR0n_β is also expressed as XR0n_s. In the following, each of XG0n_α and XG0n_β is also expressed as XG0n_s. In the following, each of XB0n_α and XB0n_β is also expressed as XB0n_s.

  In the following, each of ZR0n_α and ZR0n_β is also expressed as ZR0n_s. In the following, each of ZG0n_α and ZG0n_β is also expressed as ZG0n_s. Hereinafter, each of ZB0n_α and ZB0n_β is also expressed as ZB0n_s.

  Since “n” in XR0n_s, XG0n_s, XB0n_s, ZR0n_s, ZG0n_s, and ZB0n_s is the same as “n” in IRn_α described above, detailed description will not be repeated. Further, “s” in XR0n_s, XG0n_s, XB0n_s, ZR0n_s, ZG0n_s, and ZB0n_s is the mode identifier α or β.

  In the calculation process K, XR0n_s, XG0n_s, XB0n_s, ZR0n_s, ZG0n_s, and ZB0n_s, which are tristimulus values of R, G, and B, are calculated for each luminance mode. More specifically, in the calculation process K, the target luminances YRT_s, YGT_s, YBT_s calculated in step S70 and the chromaticity values xR0n_s, xG0n_s, xB0n_s, yR0n_s, yG0n_s, yB0n_s specified in the chromaticity specification process are obtained. Is substituted into the following equation 2. Thereby, XR0n_s, XG0n_s, XB0n_s, ZR0n_s, ZG0n_s, and ZB0n_s are calculated for each luminance mode.

  Here, as an example, a process performed by the microcomputer 43 of the master device Ma in the arithmetic process K (S125) will be described. In the calculation process K (S125), the microcomputer 43 of the master device Ma calculates the target luminances YRT_α, YGT_α, YBT_α calculated in step S70 and the chromaticity values xR0n_α, xG0n_α, xB0n_α, yR0n_α, yG0n_α, yB0n_α. Assign to. Thereby, the microcomputer 43 calculates XR0n_α, XG0n_α, XB0n_α, ZR0n_α, ZG0n_α and ZB0n_α corresponding to the normal mode (group α).

  In the arithmetic process K (S125N), the microcomputer 43 of the slave device Sb in the normal mode calculates XR0n_α, XG0n_α, XB0n_α, ZR0n_α, ZG0n_α, and ZB0n_α as in step S125.

  Further, in the calculation process K (S125L), the microcomputer 43 of each slave device S in the power saving mode calculates XR0n_β, XG0n_β, XB0n_β, ZR0n_β, ZG0n_β, and ZB0n_β similarly to step S125.

  In the following, the target stimulus values corresponding to the group α and corresponding to R are also expressed as XRT_α and ZRT_α. In the following, target stimulation values corresponding to the group α and corresponding to G are also expressed as XGT_α and ZGT_α. In the following, the target stimulus values corresponding to the group α and corresponding to B are also expressed as XBT_α and ZBT_α.

  In the following, the target stimulus values corresponding to the group β and corresponding to R are also expressed as XRT_β and ZRT_β. In the following, target stimulation values corresponding to group β and corresponding to G are also expressed as XGT_β and ZGT_β. In the following, the target stimulus values corresponding to the group β and corresponding to B are also expressed as XBT_β and ZBT_β.

  In the following, each of XRT_α and XRT_β is also expressed as XRT_s. In the following, each of XGT_α and XGT_β is also expressed as XGT_s. In the following, each of XBT_α and XBT_β is also expressed as XBT_s.

  In the following, each of ZRT_α and ZRT_β is also expressed as ZRT_s. In the following, each of ZGT_α and ZGT_β is also expressed as ZGT_s. In the following, each of ZBT_α and ZBT_β is also expressed as ZBT_s.

  “S” in XRT_s, ZRT_s, XGT_s, ZGT_s, XBT_s, and ZBT_s is the mode identifier α or β.

  Further, in the arithmetic process K, XRT_s, ZRT_s, XGT_s, ZGT_s, XBT_s, and ZBT_s, which are the target tristimulus values of R, G, and B, are calculated for each luminance mode.

  More specifically, in the calculation process K, the target luminances YRT_s, YGT_s, YBT_s calculated in step S70 and the target chromaticities xRT_s, xGT_s, xBT_s, yRT_s, yGT_s, yBT_s calculated in step S123 are as follows. Is substituted into Equation (3). Thereby, XRT_s, ZRT_s, XGT_s, ZGT_s, XBT_s, and ZBT_s are calculated for each luminance mode.

  Here, as an example, a process performed by the microcomputer 43 of the master device Ma in the arithmetic process K (S125) will be described. In the calculation process K (S125), the microcomputer 43 of the master device Ma substitutes the target luminance values YRT_α, YGT_α, YBT_α and the target chromaticities xRT_α, xGT_α, xBT_α, yRT_α, yGT_α, yBT_α into Equation 3. Thereby, the microcomputer 43 calculates XRT_α, ZRT_α, XGT_α, ZGT_α, XBT_α, and ZBT_α corresponding to the normal mode (group α).

  Further, in the calculation process K (S125N), the microcomputer 43 of the slave device Sb in the normal mode calculates XRT_α, ZRT_α, XGT_α, ZGT_α, XBT_α, and ZBT_α similarly to step S125.

  Further, in the calculation process K (S125L), the microcomputer 43 of each slave device S in the power saving mode calculates XRT_β, ZRT_β, XGT_β, ZGT_β, XBT_β, and ZBT_β similarly to step S125.

  Hereinafter, the video signal (digital video signal) input to the video processing circuit 42 of the projection video display device 100 is also expressed as video signals Ri, Gi, and Bi. The video signals Ri, Gi, Bi are the same as Ri, Gi, Bi in Equation 1.

  In the following, tristimulus values corresponding to the group α and corresponding to the video signals Ri, Gi, Bi are also expressed as Xn_α, Yn_α, Zn_α. In the following, tristimulus values corresponding to the group β and corresponding to the video signals Ri, Gi, Bi are also expressed as Xn_β, Yn_β, Zn_β.

  In the following, each of Xn_α and Xn_β is also expressed as Xn_s. In the following, each of Yn_α and Yn_β is also expressed as Yn_s. Hereinafter, each of Zn_α and Zn_β is also expressed as Zn_s.

  Since “n” in Xn_s, Yn_s and Zn_s is the same as “n” in IRn_α described above, detailed description will not be repeated. Further, “s” in Xn_s, Yn_s, and Zn_s is the mode identifier α or β.

  Here, Xn_s, Yn_s, and Zn_s, which are tristimulus values for the video signals Ri, Gi, Bi, are expressed by the following Expression 4.

  In the following, the correction coefficients RR, RG, RB, GR, GG, GB, BR, BG, and BB of Equation 1 corresponding to the group α and corresponding to the numbers indicated by the ID numbers are respectively corrected coefficients RRn_α. , RGn_α, RBn_α, GRn_α, GGn_α, GBn_α, BRn_α, BGn_α, and BBn_α.

  In the following, correction coefficients RR, RG, RB, GR, GG, GB, BR, BG, BB corresponding to the group β and corresponding to the number indicated by the ID number are respectively corrected coefficient RRn_β, Also expressed as RGn_β, RBn_β, GRn_β, GGn_β, GBn_β, BRn_β, BGn_β, BBn_β.

  In the following, correction coefficients RRn_α, RGn_α, RBn_α, GRn_α, GGn_α, GBn_α, BRn_α, BGn_α, BBn_α and correction coefficients RRn_β, RGn_β, RBn_β, GRn_β, Gn_β, Gn_β, Gn_β, Gn_β, Coefficients RRn_s, RGn_s, RBn_s, GRn_s, GGn_s, GBn_s, BRn_s, BGn_s, BBn_s are also written.

  Since “n” in the correction coefficients RRn_s, RGn_s, RBn_s, GRn_s, GGn_s, GBn_s, BRn_s, BGn_s, and BBn_s is the same as “n” of IRn_α described above, detailed description will not be repeated. Further, “s” in the correction coefficients RRn_s, RGn_s, RBn_s, GRn_s, GGn_s, GBn_s, BRn_s, BGn_s, BBn_s is the mode identifier α or β.

  Formula 1 and Formula 1 in which correction coefficients RR, RG, RB, GR, GG, GB, BR, BG, and BB are replaced with RRn_s, RGn_s, RBn_s, GRn_s, GGn_s, GBn_s, BRn_s, BGn_s, and BBn_s, respectively. From Equation 4, the following Equation 5 is obtained.

  Next, the microcomputer 43 of each projection display apparatus 100 performs a correction coefficient calculation process (S126, S126N, S126L). That is, the microcomputer 43 of each of the master device Ma and the slave devices Sb, Sc, Sd performs a correction coefficient calculation process.

  In the correction coefficient calculation process, the microcomputer 43 of each projection display apparatus 100 calculates a correction coefficient corresponding to the set luminance mode of the projection display apparatus 100. The correction coefficient is a correction coefficient for correcting the level of the video signal input to the projection display apparatus 100. Further, the correction coefficient is a coefficient for making the video chromaticity of the projection video display devices 100 in the same luminance mode the same. The correction coefficients are the aforementioned correction coefficients RRn_s, RGn_s, RBn_s, GRn_s, GGn_s, GBn_s, BRn_s, BGn_s, and BBn_s.

  More specifically, in the correction coefficient calculation process, the microcomputer 43 of each projection display apparatus 100 enters the set brightness mode based on the target chromaticity corresponding to the set brightness mode of the projection display apparatus 100. The corresponding correction coefficient is calculated.

  Specifically, in the correction coefficient calculation process, the microcomputer 43 of each projection display apparatus 100 calculates the target luminances YRT_s, YGT_s, YBT_s calculated in step S70 and XR0n_s, ZR0n_s, XG0n_s calculated in the calculation process K. , ZG0n_s, XB0n_s, and ZB0n_s, and XRT_s, ZRT_s, XGT_s, ZGT_s, XBT_s, and ZBT_s calculated by the arithmetic processing K are substituted into Equation 5. Thereby, the microcomputer 43 calculates the correction coefficients RRn_s, RGn_s, RBn_s, GRn_s, GGn_s, GBn_s, BRn_s, BGn_s, BBn_s.

  Here, as an example, a process performed by the microcomputer 43 of the master device Ma in the correction coefficient calculation process (S126) will be described. In the correction coefficient calculation process (S126), the microcomputer 43 of the master device Ma performs the target luminances YRT_α, YGT_α, YBT_α, XR0n_α, ZR0n_α, XG0n_α, ZG0n_α, XB0n_α, ZB0n_α, XRT_α, ZRT_α, BGT_α, XGT_α, BGT Are substituted into Equation 5. Thereby, the microcomputer 43 calculates correction coefficients RRn_α, RGn_α, RBn_α, GRn_α, GGn_α, GBn_α, BRn_α, BGn_α, BBn_α corresponding to the normal mode (group α).

  In the correction coefficient calculation process (S126N), the microcomputer 43 of the slave device Sb in the normal mode calculates the correction coefficients RRn_α, RGn_α, RBn_α, GRn_α, GGn_α, GBn_α, BRn_α, BGn_α, BBn_α as in step S126. .

  In the correction coefficient calculation process (S126L), the microcomputer 43 of each slave device S in the power saving mode uses the correction coefficients RRn_β, RGn_β, RBn_β, GRn_β, GGn_β, GBn_β, BRn_β, BGn_β, BBn_β as in step S126. calculate.

  Next, the microcomputer 43 of each projection display apparatus 100 performs chromaticity correction processing (S127, S127N, S127L). That is, the microcomputer 43 of each of the master device Ma and the slave devices Sb, Sc, Sd performs chromaticity correction processing.

  The chromaticity correction process is a process for making the video chromaticity of each projection display apparatus 100 in the same luminance mode the same by using the calculated correction coefficient.

  Here, as an example, a process performed by the microcomputer 43 of the master device Ma in the chromaticity correction process (S127) will be described. In the chromaticity correction process (S127), the video processing circuit 42 performs the above-described image quality adjustment using the calculated correction coefficients RRn_α, RGn_α, RBn_α, GRn_α, GGn_α, GBn_α, BRn_α, BGn_α, BBn_α. The microcomputer 43 controls the video processing circuit 42.

  In the chromaticity correction process (S127N), the microcomputer 43 of the slave device Sb controls the video processing circuit 42 as in step S127.

  In the chromaticity correction process (S127L), the microcomputer 43 of each slave device S controls the video processing circuit 42 as in step S127. Hereinafter, as an example, the processing of the slave device Sc will be described.

  The microcomputer 43 of the slave device Sc uses the microcomputer so that the video processing circuit 42 performs the above-described image quality adjustment using the calculated correction coefficients RRn_β, RGn_β, RBn_β, GRn_β, GGn_β, GBn_β, BRn_β, BGn_β, BBn_β. 43 controls the video processing circuit 42.

  Through the above chromaticity correction processing (S127, S127N, S127L), the video chromaticities of the projection type video display devices 100 in the same luminance mode are the same. That is, the chromaticity correction processing (S127, S127N, S127L) can suppress (prevent) the variation in the video chromaticity of each projection display apparatus 100 in the same luminance mode. Then, Steps S102M, S102N, and S102L are finished, and the luminance / chromaticity adjustment processing in FIG. 8 is finished.

  As described above, according to the present embodiment, the same processing as in the first embodiment is performed. Therefore, it is possible to suppress variation in luminance between the projection type video display devices 100 in the same luminance mode.

  Further, according to the present embodiment, the master device Ma calculates the target chromaticity by transmitting / receiving the target chromaticity to / from the slave devices S of each group for each luminance mode. Then, each projection display apparatus 100 calculates a correction coefficient for correcting the level of the video signal based on the target chromaticity corresponding to its own luminance mode. And the process for making the video chromaticity of each projection type video display apparatus 100 of the same luminance mode the same is performed using the calculated correction coefficient by the chromaticity correction process.

  Thereby, the dispersion | variation in the brightness | luminance and chromaticity between the projection type video display apparatuses 100 for every group can be suppressed. That is, it is possible to suppress variations in luminance and chromaticity between the projection type video display devices 100 in the same luminance mode. As a result, the sense of unity of the video displayed on the multi-screen display device 1000 can be improved.

  Note that if both the luminance adjustment and the chromaticity correction are performed only by correcting the level of the video signal, the gradation expression level may be impaired in each projection type video display device 100.

  On the other hand, in the present embodiment, the control current is adjusted to suppress the luminance variation. In addition, the level of the video signal is corrected to suppress variations in chromaticity. Thereby, it is possible to reduce the loss of the digital expression gradation of the video signal displayed on the screen. Therefore, the processing according to the present embodiment is particularly effective in displaying a video such as a natural image that uses many intermediate gradations.

<Embodiment 3>
In the first and second embodiments, the method for reducing variations in luminance and chromaticity in the multi-screen display device 1000 has been described.

  In the present embodiment, a user who uses multi-screen display device 1000 solves a problem that occurs when the luminance mode of each of projection-type video display devices 100 constituting multi-screen display device 1000 is changed. Processing will be described. The problem is that most of the brightness of the multi-screen display device 1000 changes. When this defect occurs, the user feels uncomfortable.

  First, as a comparative example, a process (operation) that may cause the user to feel uncomfortable will be described.

  As a premise, as shown in FIG. 10, it is assumed that the multi-screen display device 1000 is composed of four projection type video display devices 100 as in FIG. In addition, each projection display apparatus 100 performs one of steps S31, S32N, and S32L of FIG. 5 or FIG. n = 1 to 4, s = α, β). In FIG. 10, only the characteristic luminance corresponding to R is shown for ease of explanation.

  FIG. 11 is a diagram illustrating the transition of the target luminance when the luminance mode is changed in the comparative example. Note that in FIG. 11, information for explaining only the characteristic luminance and target luminance corresponding to R is shown for simplicity of explanation.

  In FIG. 11, the transition of the target luminance in the following operation stage N is shown. The operation stage N is a stage in which the variation in luminance is reduced by the processing of the first and second embodiments using the characteristic luminance YR0n_s (n = 1 to 4, s = α, β). Specifically, in FIG. 11, in the operation stage N, when the user operates the external control device 6, the luminance mode of any of the projection type video display devices 100 configuring the multi-screen display device 1000 is changed. Represents the transition of the target luminance YRT_s (s = α, β).

  Here, it is assumed that the multi-screen display device 1000 satisfies the following condition B. Condition B is that the normal mode as the luminance mode is set in the master device Ma and the slave device Sb. That is, the master device Ma and the slave device Sb belong to the group α. The condition B is that the power saving mode as the luminance mode is set in the slave devices Sc and Sd. That is, the slave devices Sc and Sd belong to the group β.

FIG. 11A shows the master device Ma and the slave devices Sb, Sc, Sd under the condition B. Note that the target luminance YRT_α corresponding to the normal mode is 790 cd / m ² . Further, the target luminance YRT_β corresponding to the power saving mode is 330 cd / m ² .

  The reason why the target luminances YRT_α and YRT_β are the above values is that the target luminances YRT_α and YRT_β are calculated according to the processing in step S70 of FIG. 5 or FIG. Specifically, for the group α, the characteristic luminance indicating the smallest value among the characteristic luminances of the master device Ma and the slave device Sb belonging to the group α is calculated as the target luminance. That is, YRT_α = Min (YR01_α, YR02_α), and the target luminance YRT_α is YR01_α.

  Further, for the group β, the characteristic luminance indicating the largest value among the characteristic luminances of the slave devices Sc and Sd belonging to the group β is calculated as the target luminance. That is, YRT_β = Max (YR03_β, YR04_β), and the target luminance YRT_β is YR03_α.

  Next, in the state of FIG. 11A, it is assumed that the user performs an operation on the external control device 6 for changing the set luminance mode of the slave device Sc from the power saving mode to the normal mode. In this case, the microcomputer 43 of the slave device Sc performs a luminance mode change process (S210) for changing the set luminance mode of the slave device Sc from the power saving mode to the normal mode.

As a result, the master device Ma and the slave devices Sb, Sc, Sd are in the state shown in FIG. That is, the devices belonging to the group α are the master device Ma and the slave devices Sb and Sc. Note that, from FIG. 10, the characteristic luminance of the slave device Sc in the normal mode is YR03_α = 780 cd / m ² .

In this case, the characteristic luminance indicating the smallest value among the characteristic luminances of the master device Ma and the slave devices Sb and Sc belonging to the group α is calculated as the target luminance YRT_α. That is, the target luminance YRT_α becomes YR03_α (780 cd / m ² ) by YRT_α = Min (YR01_α, YR02_α, YR03_α).

At the same time, the only device belonging to the group β is the slave device Sd. Therefore, the target luminance YRT_β is the characteristic luminance YR04_β (320 cd / m ² ) of the slave device Sd.

  In other words, the target luminance is changed in both the projection video display device 100 belonging to the group α and the projection video display device 100 belonging to the group β by the luminance mode changing process (S210). For this reason, the video brightness of all the projection video display devices 100 changes. That is, although the brightness mode of one projection video display apparatus 100 is only changed, the user appears to change the brightness of the entire multi-screen display apparatus 1000.

  Next, in the state of FIG. 11B, it is assumed that the user performs an operation on the external control device 6 for changing the set luminance mode of the slave device Sc from the normal mode to the power saving mode. In this case, the microcomputer 43 of the slave device Sc performs a luminance mode changing process (S220) for changing the set luminance mode of the slave device Sc from the normal mode to the power saving.

As a result, as shown in FIG. 11C, the group to which each of the master device Ma and the slave devices Sb, Sc, Sd belongs is returned to the original group in FIG. In this case, the target brightness YRT_α and YRT_β corresponding to each brightness mode become YR01_α (790 cd / m ² ) and YR03_α (330 cd / m ² ), respectively, by performing the process of step S70.

  Through the brightness mode changing process (S220), the target brightness is changed in both the projection display apparatus 100 belonging to the group α and the projection display apparatus 100 belonging to the group β. For this reason, the video brightness of all the projection video display devices 100 changes. That is, although the brightness mode of one projection video display apparatus 100 is only changed, the user appears to change the brightness of the entire multi-screen display apparatus 1000.

  That is, in the comparative example, when the brightness mode change process (S210) or the brightness mode change process (S220) is performed, the brightness mode of one projection video display device 100 is only changed. The user appears to change the brightness of the entire multi-screen display device 1000. As a result, the user may feel uncomfortable.

  Further, in the comparative example, as described above, the minimum characteristic luminance indicating the smallest value among the characteristic luminances of the projection video display devices 100 belonging to the group α is calculated as the target luminance. In this case, when the luminance mode of the projection display apparatus 100 corresponding to the minimum characteristic luminance is changed, the minimum characteristic luminance in each projection display apparatus 100 belonging to the luminance mode before the change is changed.

  At this time, if the target brightness is changed, the target brightness is changed again when the brightness mode of the projection display apparatus 100 whose brightness mode has been changed becomes the brightness mode before the change. Therefore, the brightness of the entire multi-screen display device 1000 frequently changes despite only changing the brightness mode of one projection video display device 100. For this reason, the user who is watching the multi-screen 10A may feel uncomfortable because it feels like the video flickers.

  Therefore, in the present embodiment, when the luminance mode of the projection display apparatus 100 is changed, the target luminance corresponding to the changed luminance mode is calculated according to the following target luminance calculation process A1. The target luminance calculation process A1 is executed when the luminance mode of a part of the plurality of projection type video display devices constituting the multi-screen display device 1000 is changed. The target brightness calculation process A1 includes a target brightness calculation process AN and a target brightness calculation process AL.

  The target brightness calculation process AN is a process for calculating the target brightness corresponding to the group α (normal mode). The target brightness calculation process AL is a process for calculating the target brightness corresponding to the group β (power saving mode). Hereinafter, each of the target luminance calculation processes AN and AL is also simply referred to as target luminance calculation process A.

  Here, the multi-screen display device according to the present embodiment is the multi-screen display device 1000 of FIG.

  In step S70 of FIG. 5 in the first embodiment, for the group α, the characteristic luminance showing the smallest value among the characteristic luminances of the projection video display devices 100 belonging to the group α is calculated as the target luminance. Is done. In addition, for the group β, the characteristic luminance indicating the largest value among the characteristic luminances of the projection video display devices 100 belonging to the group β is calculated as the target luminance.

  Hereinafter, among the characteristic luminances of the projection video display devices 100 belonging to the group α, the characteristic luminance indicating the smallest value is also referred to as the minimum characteristic luminance. In addition, among the characteristic luminances of the projection video display devices 100 belonging to the group β, the characteristic luminance indicating the largest value is also referred to as the maximum characteristic luminance.

  In the target luminance calculation process A, before adopting the minimum characteristic luminance or the maximum characteristic luminance as the target luminance after changing the luminance mode, the minimum characteristic luminance or the maximum characteristic luminance is set as a target luminance candidate. In the following, when the luminance mode of the projection display apparatus 100 is changed, the changed luminance mode is also referred to as a changed luminance mode. In the following, the target luminance corresponding to the changed luminance mode is also referred to as changed target luminance.

  Hereinafter, the target luminance calculation process AN and the target luminance calculation process AL will be specifically described. In the target brightness calculation process A1, each of the target brightness calculation process AN and the target brightness calculation process AL is independently performed in parallel.

  In summary, in each of the target luminance calculation processing AN and the target luminance calculation processing AL, the microcomputer 43 of the master device Ma is configured so that the difference between the already calculated target luminance and the changed target luminance is minimized. The change target brightness is calculated.

  FIG. 12 is a flowchart of the target luminance calculation process A1. The target luminance calculation process A1 is performed by the master device Ma. As described above, the target brightness calculation process A1 includes the target brightness calculation process AN and the target brightness calculation process AL. Hereinafter, the target luminance already calculated in step S70 of FIG. 5 or FIG. 8 is also referred to as calculated target luminance. The calculated target luminance is the latest target luminance in each projection video display device 100.

  In the following, the calculated target luminance corresponding to the group α (normal mode) is also referred to as the calculated target luminance α. The calculated target luminance α is YRT_α, YGT_α, YBT_α. In the following, the calculated target luminance corresponding to the group β (power saving mode) is also referred to as the calculated target luminance β. The calculated target brightness β is YRT_β, YGT_β, YBT_β.

  First, the target luminance calculation process AN will be described. In the target luminance calculation process AN, the microcomputer 43 sets the minimum characteristic luminance as the comparison target luminance (S310N). The target brightness for comparison is the brightness used for comparison. Next, the microcomputer 43 compares the target luminance for comparison with the calculated target luminance (S320N). Next, the microcomputer 43 calculates a target luminance having a smaller value among the comparison target luminance and the calculated target luminance as the changed target luminance (S330N).

  Next, the target luminance calculation process AL will be described. In the target luminance calculation process AL, the microcomputer 43 sets the maximum characteristic luminance as the comparison target luminance (S310L). Next, the microcomputer 43 compares the target luminance for comparison with the calculated target luminance (S320L). Next, the microcomputer 43 calculates a target luminance having a larger value among the comparison target luminance and the calculated target luminance as the changed target luminance (S330L).

  Next, specific processes of the target brightness calculation process AN and the target brightness calculation process AL will be described with examples. Hereinafter, for the sake of simplicity, a process for calculating the change target luminance corresponding to R will be described.

  FIG. 13 is a diagram for explaining target luminance calculation processing according to Embodiment 3 of the present invention. FIG. 13 shows the transition of the target luminance when the luminance mode is changed, as in FIG. Note that FIG. 13 shows information for explaining only the characteristic luminance and target luminance corresponding to R for the sake of simplicity of explanation.

  Specifically, FIG. 13 shows the luminance mode of each of the projection type video display devices 100 constituting the multi-screen display device 1000 when the user operates the external control device 6 in the operation stage N described above. Represents the transition of the target luminance YRT_s (s = α, β) when. The target brightness is calculated by the target brightness calculation process AN or the target brightness calculation process AL.

  The multi-screen display device 1000 in FIG. 13A has the same configuration as the multi-screen display device 1000 in FIG. That is, the multi-screen display device 1000 has the same luminance mode and the same characteristic luminance as the multi-screen display device 1000 of FIG.

  Next, in the state of FIG. 13A, it is assumed that the user performs an operation on the external control device 6 for changing the set luminance mode of the slave device Sc from the power saving mode to the normal mode. In this case, the microcomputer 43 of the slave device Sc performs a luminance mode change process (S210) for changing the set luminance mode of the slave device Sc from the power saving mode to the normal mode.

As a result, the master device Ma and the slave devices Sb, Sc, Sd are in the state shown in FIG. That is, the devices belonging to the group α are the master device Ma and the slave devices Sb and Sc. Note that, from FIG. 10, the characteristic luminance of the slave device Sc in the normal mode is YR03_α = 780 cd / m ² .

  Further, the target luminance calculation process A1 is performed according to the change of the luminance mode of the slave device Sc. That is, the target luminance calculation process AN and the target luminance calculation process AL are performed.

In the target luminance calculation processing AN, first, the microcomputer 43 uses YR03_α (780 cd / m ² ) as the minimum characteristic luminance among the characteristic luminances of the master device Ma and the slave devices Sb and Sc belonging to the group α as a comparison target luminance. (S310N).

Next, the microcomputer 43 compares the target luminance for comparison (780 cd / m ² ) with the current calculated target luminance (790 cd / m ² ) (S320N). Next, the microcomputer 43 calculates a comparison target brightness having a smaller value among the comparison target brightness and the calculated target brightness as the changed target brightness (S330N).

At the same time, the only device belonging to the group β is the slave device Sd. Therefore, in the target luminance calculation process AL, first, the microcomputer 43 sets YR04_β (320 cd / m ² ) as the maximum characteristic luminance among the characteristic luminances of the slave devices Sd belonging to the group β as the comparison target luminance (S310L). ).

Next, the microcomputer 43 compares the target brightness for comparison (320 cd / m ² ) with the current calculated target brightness (330 cd / m ² ) (S320L). Next, the microcomputer 43 calculates a calculated target brightness having a larger value among the comparison target brightness and the calculated target brightness as the changed target brightness (S330L). That is, the current calculated target brightness is maintained as it is as the target brightness of the group β (see FIGS. 13A and 13B).

  Then, using the changed target brightness calculated by the target brightness calculation processes AN and AL as new target brightness, steps S81, S82N, S82L, S91, S92N, S92L, S93, S94n, and S94L in FIG. Is done. Thereby, in each projection type video display apparatus 100 of the same luminance mode, the video luminance is controlled according to the changed target luminance.

  In this case, unlike the process of FIG. 11, in the process of FIG. 13 in which the target brightness calculation processes AN and AL are performed, the target brightness of only the projection display apparatus 100 belonging to the group α is changed. Therefore, according to the present embodiment, the video brightness of only the master device Ma and the slave devices Sb and Sc is changed, not the entire multi-screen display device 1000 as in the comparative example.

  Next, in the state of FIG. 13B, it is assumed that the user performs an operation on the external control device 6 to change the set luminance mode of the slave device Sc from the normal mode to the power saving mode. In this case, the microcomputer 43 of the slave device Sc performs a luminance mode changing process (S220) for changing the set luminance mode of the slave device Sc from the normal mode to the power saving.

  As a result, as shown in FIG. 13C, the group to which each of the master device Ma and the slave devices Sb, Sc, Sd belongs is returned to the original group in FIG.

  Further, the target luminance calculation process A1 is performed according to the change of the luminance mode of the slave device Sc. That is, the target luminance calculation process AN and the target luminance calculation process AL are performed.

In the target luminance calculation processing AN, first, the microcomputer 43 sets YR01_α (790 cd / m ² ) as the minimum characteristic luminance among the characteristic luminances of the master device Ma and the slave device Sb belonging to the group α as the comparison target luminance. (S310N).

Next, the microcomputer 43 compares the target luminance for comparison (790 cd / m ² ) with the current calculated target luminance (780 cd / m ² ) (S320N). Next, the microcomputer 43 calculates a calculated target brightness having a smaller value among the comparison target brightness and the calculated target brightness as the changed target brightness (S330N). That is, the current calculated target brightness is maintained as it is as the target brightness of the group α (see FIGS. 13B and 13C).

At the same time, a slave device Sc is added as a device belonging to the group β. Therefore, in the target luminance calculation process AL, first, the microcomputer 43 sets YR03_β (330 cd / m ² ) as the maximum characteristic luminance among the characteristic luminances of the slave devices Sc and Sd belonging to the group β as the comparison target luminance. (S310L).

Next, the microcomputer 43 compares the target brightness for comparison (330 cd / m ² ) with the current calculated target brightness (330 cd / m ² ) (S320L). Next, the microcomputer 43 calculates a target luminance (330 cd / m ² ) having a larger value among the comparison target luminance and the calculated target luminance as the changed target luminance (S330L). That is, the current calculated target luminance is maintained as it is as the target luminance of the group β (see FIGS. 13B and 13C).

  Therefore, according to the present embodiment, as described with reference to FIG. 13, the luminance mode changing process (S210) and the luminance mode are performed except for the change in the video luminance according to the active luminance mode change by the user. Of the changing process (S220), only when the luminance mode changing process (S210) is performed, the video brightness of the master device Ma and the slave devices Sb and Sc is changed.

  Although only R is described in FIG. 13, the same processing as R is performed for G and B.

  In the comparative example of FIG. 11, when each of the luminance mode changing process (S210) and the luminance mode changing process (S220) is performed, the video brightness of all the projection video display devices 100 is changed.

  On the other hand, in the present embodiment, except for a change in video luminance in response to an active luminance mode change by the user, a target luminance calculation process AN and a target luminance calculation process AL are performed, thereby performing a luminance mode change process ( Only when S210) is performed, the video brightness of the master device Ma and the slave devices Sb, Sc only changes.

  Therefore, according to the present embodiment, when the user performs an operation for changing any of the brightness modes of the projection display apparatus 100, only the brightness mode (group) that needs to be changed in the target brightness, The video brightness is changed. Therefore, it is possible to prevent the image brightness from being changed unnecessarily by changing the brightness mode. As a result, the user can be prevented from feeling uncomfortable.

  In the present embodiment, the case where the luminance mode of one projection display apparatus 100 is changed has been described. However, the processing in the present embodiment is applicable even when the luminance mode of two or more projection type video display devices 100 is changed.

(Other variations)
Although the multi-screen display device according to the present invention has been described based on the embodiments, the present invention is not limited to these embodiments. The present invention also includes modifications made to the present embodiment by those skilled in the art without departing from the scope of the present invention. In other words, the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  Further, the projection display apparatus 100 of the multi-screen display apparatus 1000 may not include all the components shown in FIG. That is, the projection display apparatus 100 needs to include only the minimum components that can realize the effects of the present invention.

  In addition, the present invention may be realized as a luminance adjustment method in which the operation of a characteristic component included in the projection display apparatus 100 is a step. In the present invention, the computer may execute each step included in the brightness adjustment method. Further, the present invention may be realized as a program that causes a computer to execute each step included in such a luminance adjustment method. Further, the present invention may be realized as a computer-readable recording medium that stores such a program. The program may be distributed via a transmission medium such as the Internet.

  All the numerical values used in the above-mentioned embodiment are examples of numerical values for specifically explaining the present invention. That is, the present invention is not limited to the numerical values used in the above embodiments.

  Further, the brightness adjustment method according to the present invention corresponds to, for example, the brightness adjustment process of FIG. 5 or the brightness chromaticity adjustment process of FIG. The order in which each process in the brightness adjustment method is executed is an example for specifically explaining the present invention, and may be an order other than the above. Further, part of the processing in the luminance adjustment method and other processing may be executed in parallel independently of each other. It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  34, 34B, 34G, 34L, 34R Light source, 43 Microcomputer, 44 Memory, 100, 100a, 100b, 100c, 100d Projection image display device, 1000 Multi-screen display device, Ma master device, S, Sb, Sc, Sd Slave apparatus.

Claims (4)

A multi-screen display device that displays video on a multi-screen composed of the screens of a plurality of projection-type video display devices that communicate with each other,
Each of the plurality of projection-type image display devices includes:
Emits light with a luminance corresponding to the supplied current, and includes a light source composed of a semiconductor light emitting element,
Each of the projection type video display devices is set with any one of a plurality of types of luminance modes having different video luminances as video luminances displayed by the projection type video display device using light emitted from the light source. ,
Each of the plurality of projection type video display devices further includes:
A storage unit that stores a luminance characteristic that is a characteristic indicating a relationship between a control current of the light source and the video luminance as a luminance corresponding to the control current;
The first projection type video display device which is one of the plurality of projection type video display devices,
The video brightness that can be output by the first projection type video display device, and the video that can be output by a second projection type video display device other than the first projection type video display device among the plurality of projection type video display devices. A calculation unit that calculates a target luminance, which is a target luminance, for each of the luminance modes based on the luminance;
Each of the projection-type image display devices is
(A) a value of the control current corresponding to the target brightness calculated corresponding to the brightness mode set in the projection display apparatus using the brightness characteristics, and the target and Identify the control current value
(B) A multi-screen display device that supplies a current indicating the specified control current value to the light source of the projection display. Each of the projection type video display devices receives a video signal,
The calculation unit further includes a chromaticity corresponding to the control current value specified by the first projection video display device, the luminance mode set in the first projection video display device, and the second A target chromaticity that is a target chromaticity based on the chromaticity corresponding to the control current value specified by the projection display apparatus and the luminance mode set in the second projection display apparatus. For each of the luminance modes,
Each of the projection type video display devices corresponds to the set luminance mode based on the target chromaticity corresponding to the set luminance mode that is the luminance mode set in the projection type video display device. The multi-screen display device according to claim 1, wherein a correction coefficient for correcting a level of the video signal input to the video display device is calculated. The calculation unit further includes the target luminance that has already been calculated when the luminance mode of a part of the plurality of projection video display devices is changed, and the target corresponding to the changed luminance mode. The multi-screen display device according to claim 1, wherein the change target luminance is calculated so that a difference from the change target luminance that is luminance is minimized. Each of the projection type video display devices communicates with an external arithmetic device,
The multi-screen display device according to claim 1, wherein the arithmetic device calculates the target luminance instead of the calculation unit.

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